Home | Aquarium Equipment | Adding a Personal Touch to Your Aquarium Décor

Adding a Personal Touch to Your Aquarium Décor

Hey, Eileen here. Ever have a certain look or item in mind for your home or wardrobe or aquarium, and were not able to find just what you wanted? Ever decide to just make it instead? Despite the huge selection of aquarium ornaments on the market today, this DIY approach is what many aquarists are beginning to turn to when the ornaments in the stores just aren’t personal enough for their own unique tanks. So, how can you get in on the action to make your tank truly your own? Here are a few tips to making your own aquarium ornaments or using non-aquarium items to personalize your aquarium.

Silicone Sealant is Your Friend

Silicone aquarium sealant can be found in almost any fish store and is usually available in clear or black. Sealants designed for aquariums are safe for fish and aquarium tankmates when fully cured, but stay away from other sealants like those used for bathroom or hardware applications. You can use sealants to make caves from pieces of rock or rubble, glue shells, stones or other decorations together, or even to cover things like PVC or plastic “caves” with substrate or rocks to form a more natural-looking hideaway.  Note: The tank in these photos has a custom background created by arranging and attaching layered slate with black silicone.  The effect of the rock wall is rather permanent, but impressive as it adds dimension.  This background was applied before the tank was set-up.

Think Outside the Box

Most rigid plastic toys, ornaments and figurines are safe for aquariums as long as they are not painted and do not have any sticker decals on them. Make sure the object is well-cleaned and any stickers or adhesives are completely removed. If you aren’t sure if it is painted or printed, try soaking it in water for awhile, then try to scrape the color off with your fingernail. If it comes off, it isn’t safe for your aquarium. You’ll also want to make sure any small pieces are removed or firmly attached with an adhesive like silicone sealants, and make sure nothing is small enough for your fish to eat.

A lot of ceramics and pottery like coffee mugs and flower pots are generally safe for aquariums, too. This is a great way to get your companies logo in that aquarium you have set up in the lobby! If a mug or plate or bowl is safe for food use, you can generally use it in your aquarium. Decorative pots that are only partially glazed or have fragile artistic glazes are not safe enough for aquariums. To see if an object will last in your aquarium, you can soak it for a few weeks in water that is the same conditions as your aquarium (or better yet, is at the extremes of your aquarium as far as temperature and pH). If it is unchanged in color, texture and strength at the end of a couple months, it should be safe to use as a decoration. Completely unglazed terracotta pottery is also perfectly suitable for aquariums.  These items can make excellent caves and breeding shelters for fish like cichlids and gobies.

Some of the only artifacts leftover from ancient shipwrecks are pottery and glassware. It may look different and become completely encrusted with corals or algaes – especially in saltwater aquariums, a problem all of these ornament ideas – but glass is very durable (which is probably why most aquariums are made from it as well).  Decorative glass bottles can be found in craft and antique stores and even very well-cleaned beer, wine and condiment bottles can be made into aquarium décor! As with the other materials listed, you’ll want to make sure there are no labels or adhesives left on the glass or bottles you decide to use and the glass should not be painted – if the glass is colored, make sure it is the glass itself that is colored, not a glaze or paint over it. You can also fill a light-colored bottle with small objects, ornaments, beads or substrates and seal the top closed to form a decorative glass “bubble” within your tank.

Cues from Nature: the Good and the Bad

Using natural items can be good and bad. In general, avoid the temptation to use something you’ve picked up off the ground since it is difficult to tell what chemicals or foreign substances may have leeched into it. Things like seashells and coral skeletons that can be cleaned VERY, VERY thoroughly in very hot water are usually safe, but avoid organic matter like starfish or wood that can decompose when put back into the water of your aquarium. Wood ornaments created for aquariums are usually safe for freshwater aquariums since they’ve already been cleaned and treated, but wood from the forest behind your house or that you’ve found at the shore is usually not a good addition to a home aquarium. If you aren’t sure if an object like a shell will affect your water quality if it is submerged, soak it in water with similar conditions to your tank and monitor the changes in color, smell, and chemistry of the water over a few weeks.  Most shells are not suitable for freshwater aquariums except african cichlid or brackish set-ups, as they may raise your pH.

The Don’ts and Disclaimers

Of course, there are always disclaimers. These tips are just to give you an idea and starting point for your own creativity.  Always make sure any non-aquarium ornaments you re-purpose for your aquarium are very clean and are safe for your fish, inverts and water chemistry before adding them to your aquarium, especially in extreme aquarium conditions like saltwater aquarium, low pH/acidic aquariums, high temperatures and sensitive or very aggressive animals. Make sure all objects are free from chemicals and sharp edges are sanded down or covered with silicone to avoid injuries to yourself or your aquarium residents. When in doubt, feel free to ask and we’ll be happy to help you figure out if your new decorating idea is a safe one!

These are just a few ideas. Be creative and let your personality shine through into your aquarium.  And, don’t forget to show us the pictures of your new, unique aquarium!



Visit the next blog in this DIY series, "Aquarium Decoration Ideas - Fish Bowl Designs & DIY" for more tips, tricks, examples and ideas!

Visit the next blog in this DIY series, “Aquarium Decoration Ideas – Fish Bowl Designs & DIY” for more tips, tricks, examples and ideas!

Part 3: More Decoration DIY: Materials and Aquarium Suitability

Read even more in Part 3 of our DIY series, “More Decoration DIY: Materials and Aquarium Suitability”!


  1. avatar


    I want to know which colors are suitable for artificial corals & reefs ,so that they are permanant in salt water, & not
    remove after cleaning…


  2. avatar

    Hi Manoj, Not exactly clear on what you’re asking…are you asking about what type of paint to use?

  3. avatar

    Yes ….exactly

    I m doing artificial coral decoration in fiber material for marine aquarium,I want to know what type of paint shall I use which should be permanent,non toxic and should not remove from the surface.

    Any help regarding this will be appreciable…Thanks

  4. avatar

    You want to use an epoxy paint, that is approved for use in potable water (drinking water). Once cured, the epoxy is very tough, and fish safe.

  5. avatar

    I would love to use a small Eiffel Tower in my Betta’s fish tank, but can only find statues made of metal. Could one of these be covered in some type of sealant to make it waterproof and ok for my betta?

  6. avatar

    I wouldn’t recommend using a metal ornament, even covered in sealant. Its possible, but if the metal got wet through a crack in the sealant or anything, it would start to rust and release chemicals, minerals or even a mild electrical current into the water. I did a web search for “eiffel tower figurine” and found some websites with glass replicas (most seemed to be wedding favors or cake toppers) that would probably be safe.

    Another option, depending how large the tank is, would be to create a “snowglobe” effect with the metal figurine by putting it in a small glass jar (some craft stores have them available) and sealing the opening closed. If you use the jar upside down, you can seal the lid and then bury it in the substrate so the jar is upsidedown and the tower is sitting on the lid of the container.

  7. avatar

    So epoxy paint will helpful for me ,but i don’t know how to use it,& from where i get that.
    Also the other thing is that I search for epoxy paint on web ,but it shows that it is to make it I have to use to many chemicals combination….
    Could u please provide me,any information about using epoxy paint & from where i get that or how to create it…


  8. avatar

    Epoxy paints become inert and they’re practically “bulletproof” when fully cured, but they can be expensive and you may not be able to purchase it in quantities less than 1 gallon…you may be able to purchase it at Lowe’s or better quality at paint stores like Sherwin Williams or even at swimming pool supply stores. You’ll be asking for paints for potable use (drinking safe) so you can ask someone at these establishments what they have available and I’m sure they’ll be able to give you detailed directions for mixing and use too. You may be able to find safe enamel type paints at craft or model shops in smaller volume, variable colors and in spray or brush on forms, though they won’t be as thick-coating or as durable as epoxy paints and may not stand up to heavy scrubbing. Do stay away from epoxy boat/marine paint as they may be chemically enhanced to deter barnicles and other inverts. May take some store visits or phone work, but try these establishments and see what they have.

  9. avatar

    so i was wondering if i could put a ceramic figure in my fresh water tank. it is made of red clay and base coloring and has been fired in the kiln. i want to put in in my tank but i am worried about my fishes 😀

  10. avatar

    Hey Jon, thanks for your question. Ceramic is an inert substance, so you’re safe! Good luck.

  11. avatar

    Terra cotta is usually ok in freshwater aquariums, you may want to submerge the item in a bucket of water to see how it holds up for a week or two. What kind of base coloring? You want to be sure it was colored with a stable, non-toxic paint or enamel that won’t leach anything into the water over time. You can test the water you soak the item in before you put it in and a few days later to be sure it won’t effect your pH.

  12. avatar

    I’m trying to decorate my tank like the bottom of a fishing lake and I wanted to put one of my old propellers and a few very large fishing lures in the tank. What would be the best way to seal these items to keep the tank safe?

  13. avatar

    Sounds like an interesting concept. Plastic or fiberglass pieces should be safe. Any pieces with wood, metal or decals can be coated in several coats of a clearcoat sealant or glaze. The best type would depend on the material but you would want to make sure it is suitable for use in water. I would recommend testing on a piece to make sure it holds up and doesn’t affect water quality before adding any pieces to the aquarium.

  14. avatar

    Hai (:
    I have a handsome male betta. im so lucky i got him, i randomly & irresponsibly picked him up from the pet store when i was out with my friends .. 😀
    I wanna make a nice tank for him. but i dont have any extra money to buy decor, etc. because im only 12 😉 so i wanted to know if there any things around the house or outsied i could use. Thannk yoouu!

  15. avatar

    hi MalMal,
    There are a lot of options that you might find around the house. Read through the “Think Outside the Box” section again and then take a look around. Glass, ceramic, colored plastic, even Legos without decals can be used. You can also take a look around your local thrift store (Goodwill, Salvation Army, etc) or a Dollar Store for decoration ideas – just remember to test everything for its safety and durability. Good luck !

    – Eileen

  16. avatar


    I’m starting up a new aquarium that’ll house a mixture of different plants and aquatic beasties. Everything is pretty much sorted except for the ornaments.

    I’ve been given a small ceramic candle holder and am wondering if you know if it is safe to use. I’ve read in this article that ceramics are generally safe however I’m not sure of the glazing that would have been used. I usually keep the mindset “if in doubt, leave out” but this candle holder would make the ideal hiding spot for fish once thoroughly cleaned.

    Is there any way I can quickly test this to see if it will be safe? I’ve been planning this tank for months and do have back-up ornaments but would like to see if I can add just a little something unique to it.

    Thank you for your time and for writing this brilliant article!

  17. avatar

    Hi Grey. Is it completely glazed? Look over the entire pieces (inside and out, top and bottom) and make sure there are no rough patches that the glazing doesn’t cover that water may soak into. If you can find out the manufacturer, you can try contacting them to see if the glaze is non-toxic, or you can soak the piece in the extremes that your tank would go through and make sure it doesn’t soften or the color doesn’t come off. If you do use it, I would still check it occasionally when you do your regular cleanings.

    All that said, I’d say you are likely safe to use it. Candleholders are designed to handle extreme temperatures and the glaze should be pretty durable. Ceramic itself is inert and should not affect the water quality.

  18. avatar


    Thank you very much for answering my query. It does seem to be completely covered in glazing and I’ll check it thoroughly again just to be sure.

    I can do some tests on it and see how it fairs, thanks again!

  19. avatar

    Hi –

    I have two goldfish that we just transplanted to a 10 gallon tank (the fish were won at a fair a year and half ago and have been living in a bubble-bowl).

    I do glass mosaic tiling and I’d like to add some kind of decoration. I’m thinking a thin, square block with the word ‘SWIM’ cut out (so the fish can swim through the letters like windows). The structure will be made of plexiglass with glass tiled applied, grouted, and sealed (grout and seal used for pool bottoms). Does that sound reasonably safe for our little fish?

    Many Thanks,


  20. avatar


    I would like to know if it is safe to use beads for the bottom of a fish tank? These beads r usually used for braclets or necklaces. And i would like to know if its safe for a crowntail betta fish.

    Questionally asking,

  21. avatar

    Sounds like it should be ok, as long as all materials are inert once cured. Keep an eye on the water chemistry for a few days after you decorate, particularly your pH just to be sure. Mosaic would also make a great background for the tank 🙂

  22. avatar

    glass and plastic beads should be fine, just make sure they are large enough not to be swallowed by the fish. I would avoid anything painted that might chip after being submerged for a long time.

  23. avatar

    I’m thinking of making a cave for my aquarium would it be safe to use a microwave plate cover that’s basically a lunch box with holes make a hole in the side and cover with gravel

    Would it be ok or would it build up chemicals?


  24. avatar

    Should be fine as you would hope anything you’re using near your food is inert 😉

  25. avatar

    I would like to know if ‘plasti-kote fast dry enamel projekt paint is safe to use on objects submersed into the aquarium?

    I want to use it for use in my terrapin tank but wood be useful for my fish as well.

    Iv searched everywhere on web and come up with nothing and to make clear I am on about the brush-on liquid paint not the spray version.

  26. avatar

    I am stunned by the prices of the plastic plants for sale in the petshops for aquariums! Is it possible to make your own with the “silk” or plastic flowers and greenery sold at hobby stores?


  27. avatar

    Plants sold in hobby stores should also be safe for tanks, be sure the base you use is waterproof and that the leaves are not painted or treated

  28. avatar

    chances are the enamel will be inert once completely cured. You may want to contact the manufacturer directly for more input on the application, they may be able to tell you for sure.

  29. avatar

    I want to put a football helmet in my tank but the logo is a sticker is there anyway to cover the sticker so it stays on I’m building a football themed tank

  30. avatar

    Hi, glad I found this post. I was wondering if this item is fish tank safe: http://www.amazon.com/Love-Never-Dies-Titanic-Skulls/dp/B003HGB3SW/ref=sr_1_1?ie=UTF8&qid=1344303967&sr=8-1&keywords=titanic+skulls It is “cold cast resin” and I heard it has some metal in it (not sure). I have a Titanic themed tank with fancy goldfish and I think this would be PERFECT! But I want it to be safe. Any thoughts? Thanks!

  31. avatar

    you could try brushing over it with a light layer of silicone or waterproof laquer, just be sure that any laquer is inert.

  32. avatar

    the resin should be inert and safe for your tank, just keep an eye out for the paint to chip…while it shouldn’t hurt the fish it may not hold up to being submerged.

  33. avatar

    Thanks! I may try some clear aquarium sealant. That’s a good idea.

  34. avatar

    hi, our clown loaches have outgrown their homes multiple times, can we use a reptile cave in our aquarium? we sanded it so there isn’t any rough edges.

  35. avatar

    Hi there i have a question for you. I have a 100 gallon tank. Would two 55 gallon filters do the trick? I just want to make sure everything is safe clean ready before I get going with the fish. Also what soap/cleaner would be best for rocks

  36. avatar

    Hi there. I am in the process of finishing up my fish tank. I have bought some figurines like these: They say they are made out of PVC plastic – will this be OK to add into my tank? Is there not some sort of Spray Paint clear coating I can use to be extra safe? Or anything else I can use to protect the fish and also the figurine over time? Thanks in advance for the help.

  37. avatar

    Hi, I have malawi cichlids..just wanted to find out if using normal kitchen tiles in my tank will be safe for my fish? Any thoughts?

  38. avatar

    shouldn’t cause any problems though you may want to monitor the pH depending on the material the cave is constructed with…resins are inert, stoneware may raise the pH

  39. avatar

    should provide sufficient filtration. The water should turn over in the tank at least 3 to four times in an hour. You can use a mild bleach solution on rocks to kill algae and sterilize, but be sure to use dechlorinator to neutralize the bleach and rinse well. You shouldn’t smell any bleach when you’re finished.

  40. avatar

    they look like they’ll be fine. Keep an eye on the paint for signs of chipping and peeling. Are they bobble heads? If so watch any areas where water can seep in, if there is a spring, it may eventually deteriorate or rust

  41. avatar

    don’t see why plain porcelain or stone tiles would pose a problem, particularly if they are meant for countertop surfaces. You may want to clean them thouroughly to ensure any debris or coatings are removed to be safe.

  42. avatar

    can i spay paint a rock and put it in a saltwater tank? could i do that for a koi pond?

  43. avatar

    You’ll have to be very careful with the paint you choose. There are paint types designed for aquatic applications that are inert when cured and formulated to hold up in water.

  44. avatar

    I want to make a rock reef decoration in my fresh water tank. Is there any problems with using rocks purchased from a home and garden center how should I clean them? I saw a reply that said use a mild solution of bleach for sterilizing, how much bleach to water is considered a mild solution?

  45. avatar

    Hey, I’m about to upgrade my current tank and am looking for exciting decorations… I have a sheep’s skull that I found in a field once which has been bleached by the sun and had the flesh boiled away from it. I was wondering if I covered it in sealant or some kind of aquarium resin, would it be okay? It would look pretty awesome and my cories would look pretty cute hiding in the eye sockets.

  46. avatar

    As long as it is thouroughly cleaned and you use a food grade or entirely inert sealant, it should be ok. Keep an eye on your pH as any bone that breaks down could affect the alkalinity of the water.

  47. avatar

    I recently dismantled my fresh water tank and went to salt water for the beauty and wider variety of fish, my question is can I use some of my old decorations, fake skull, lil skull towers, etc, in my t
    Salt water tank now? Heard fake decorations are a no no but thought that was meant for the brightly colored stuff like sponge bob pineapple house

  48. avatar

    Thanks for the response. I’ve spent the last couple of weeks bleaching, cleaning and drying out the skull now I just need to seal it. Do you have any idea on what I could use to do so? Most aquarium sealant comes in small tubes and I’m not sure how well it would cover such a large item, a few people have suggested Krylon Fusion but that’s not available in the UK as far as I’m aware 🙁

  49. avatar

    I think it really depends on who manufactured the ornament, some are made to be safe in fresh or saltwater, others only for fresh. You can put the ornament in the tank, just keep an eye on it for shipping or flaking of the paint, if it starts, probably best to remove it.

  50. avatar

    look at your local hardware or home improvement store for clear 100% silicone caulk. Make sure it doesn’t contain antimicrobial or other additives, and let it cure for at least 48 hours.

  51. avatar

    If I am looking to use an alternative for gravel in a small beta fish tank, could a beaded necklace work? I think this would be both decorative and easier to maintain as I could simply pull on the beaded string for cleanings to get all of the detritus and debris free for cleaning times. Are beads like this safe to use? Is this a plausible idea?

  52. avatar

    I’m sure a necklace would be fine, may want to look for one with colored plastic or glass beads…painted plastic ones will start to chip. Good luck.

  53. avatar

    i want to buy a cold cast poly resin bronze mermaid for my new saltwater tank?? no fish yet..but will it b ok? dont wanna spend lots of cash on it..if its gonna deteriate.

  54. avatar

    polyresin or bronze? Polyresin ornaments are generally safe for fresh or salt though a close eye should be kept on any paint or finish to watch for peeling or chipping. Bronze will not be a good idea in a closed saltwater system.

  55. avatar

    are dollar general terra cotta pots safe for tropical fish

  56. avatar

    they should be fine, just be sure to clean them first

  57. avatar
    Catherine Perry

    I have a brass figurine that I’m considering for a decorative piece in my Betta fish bowl. It is two elephants on a bench under an umbrella reading a book.

    My question is: Would the brass object make my Betta sick?

  58. avatar

    Brass is questionable…not sure how long it will hold up submerged, and as far as the toxicity probably better not to add it in such a small volume of water to be safe.

  59. avatar

    I have a hockey puck with a decal on it that I would like to make safe for my betta tank (Hockey theme!). What is the best way to seal it or what should I buy to cover it to make it safe for the tank and keep the decal on? I think the puck is make out of some sort of hard rubber?

  60. avatar

    A layer of aquarium sealant on the whole puck should do the trick. The silicone layer will make the decal waterproof, and the rubber should be inert.

  61. avatar

    Hi, I would like to have a wvu football themed tank and I found a stadium replica http://www.homefields.com/pc-75-8-west-virginiamountaineer-field.aspx
    And I was wondering if I can put this in my tank. I do not know if its safe for the fish.

  62. avatar

    You may want to contact the supplier and find out what these models are made of and what kind of paint is used. Chances are the non-lighted models will not pose a threat to your tank, but there is little info on the construction at the link you provided.

  63. avatar

    Love the article by the way! I just got myself a 180 gallon glass tank and will be setting it up as a salt water tank for shark and rays. I want to have a beautiful tank but in keeping it perfect and safe for the rays and shark I want the tank to be as empty as possible with just a background, hide tunnel, and natural sand. I was thinking that it would be really neat to have a glass tile mosaic background. Very similar to how a kitchen back splash is, or a fully tiled shower. It would be glass tiles, that are grouted and sealed just like how it is for a pool then sealed with aquarium sealant. Now my major concern is the weight that the tile and grout and all would put on the glass. I know mosaic peaces can be very heavy and I’m concerned the glass wouldn’t be strong enough to hold the weight for that plus the water and fish and all. I haven’t seen ANY tanks done this way but I think it would be just stunningly beautiful. Any thoughts would be helpful on this. Thank you.

  64. avatar

    Hi i just got a goldfish from a carnival and they gave me one of those small tanks with it im only 13 so i dont have alote money and im wondering how to take good care of it without having to pay a fortune.

  65. avatar

    We’ve done backgrounds with wood and slate and they have held up, the mosaic shouldn’t be a problem and sounds like it would be a fantastic backdrop!

  66. avatar

    You can actually read about carnival fish here: http://blogs.thatpetplace.com/thatfishblog/2008/05/15/carnival-fish-part-1/ if it helps. The important thing about goldfish is providing enough space and a clean environment.

  67. avatar

    my comet goldfish lik variety (food status)

  68. avatar

    I have a hollow glazed ornament from the circle of love collection. I filled it with the tank water and submerged it. It looked fantastic but I was advised it could leach into the water and poison my fish. If I fill with sand and seal the bottom completely so that only the glaze is in the water will it be okay? Many thanks

  69. avatar

    what is the ornament made of? If it is glazed ceramic it is probably inert. a coating of clear silicone will seal it completely.

  70. avatar

    Yes it is glazed ceramic, I can only find silicone sealant, is that what you mean? If not where do I find it? Many thanks

  71. avatar


    I’m setting up a hermit crab enclosure and I’m just wondering what I should use. I want to put some substrate down the end of my enclosure that descends down into salt water to represent a shoreline. But i need to put a sealant over the substrate so that the water stays there and that it doesn’t flood the rest of the tank. What should I use?


  72. avatar

    yes, 100% silicone sealant should do the trick if you’re concerned

  73. avatar

    you can use clear silicone sealant which is inert when fully dry or cured

  74. avatar

    How do I put it all over the substrate without it moving?

  75. avatar

    best bet would probably be to combine the silicone with the substrate to make a composite, then use it to create a short barrier between the water and the rest of the substrate. Does that make sense?

  76. avatar

    Yes that is a great idea!!! THANKYOU so much 🙂

  77. avatar

    Can I use a fishing lure for a decoration in my tanks and could I also use a hamster tube as a kind of “tunnel?”

  78. avatar

    hey i want to give a 3d look to my aquarium in background,so i thought of using rock design exterior tiles in the background,what should i use to stick tiles and is it a good idea of using the tiles. ur help will be appreciable 😉

  79. avatar

    Both should be usable as they should both be inert.

  80. avatar

    What material are the tiles? You want to be sure the material is inert so it won’t effect the water chemistry. 100 percent silicone aqquarium sealant can be used to adhere tile or rock to the glass.

  81. avatar

    Would it be possible to but non painted, plastic jewelry beads that i bought from a store in a fish tank?

  82. avatar

    Hi! I just got a betta fish, and i really would Like to make the tank my own, but i. Dont want to put anything in there, the fish is really beautiful and i would be really sad if something bad happens! Lol. I got this idea to put One of my action figurines from a tv serie i Like :p it would Look awsome! I did some research and the figurine itself is made of pvc plastic. There are no metal joins either! I soaked it in very hot water for several minutes. Then i did tried to scrape the color off with my fingernail and absolutly Nothing came off. So here is my question, after all those tests, is there Anthing else i should be aware of before to put my action figurine in my fish tank That could arm my fish?

  83. avatar

    Of course! I would clean them thouroughly first though 🙂

  84. avatar

    We use action figures in some store displays, they are just fine! Go for it!

  85. avatar

    Hi, i got this rubber snake toy for a present and i would like to put in my fish tank..
    would it be safe if i was to steralize it?? its kinda rubbery and soft.. the snake

  86. avatar

    Hi Bridgette,

    I don’t think that’ll be a problem. I would wash it with hot water first, but nothing too extreme. Most rubber toys tend to be fairly inert – so you should be fine. In the outside chance something would leech from it – having carbon in your filter (which comes standard with most) should neutralize it. We’d love to see your tank once it’s setup. If you have time, post a picture on facebook.com/thatpetplace.

  87. avatar

    I made some clay pieces for my fish tank what would be the best thing to seal it with. I have fresh water African cichlids, I was wondering if epoxy paint or lead free glaze (food safe) would seal it.

  88. avatar

    Hi Mel, Any food-safe glazes should be safe. I would look it over carefully to make sure there are no spots that the glaze missed or even double-glaze it to be safe but otherwise, that should be fine for the aquarium.

  89. avatar

    Hi, I’m trying to figure something out. Is it possible to create a decoration out of Legos or something else that can be attached together? I would like to have something that I can take out and change at will, but can’t find the right material to do it. I don’t have any sort of unusual type of aquarium, just a baby snapping turtle and some fish from time to time, and no salt of acids are in it. Thanks in advance!

  90. avatar

    Hi Levi, Legos would be a good choice! I would look for ones without any decals but plain plastic solid-colored blocks work great. You may need to experiment with weighting them down but they are safe for use in the aquarium. Bigger building blocks would work too. You can also try stacking unpainted terracotta pots to form pyramids or gluing together PVC of various sizes (although those “ornaments” are a little more permanent once attached together).

  91. avatar

    Thank you! Lots of those types of toys laying around my home, now I can find some use for them.

  92. avatar

    Hey, I have a 45gal freshwater aquarium and I was wondering could I put dead coral in or to I need to coat it with something first?

  93. avatar

    Hi Susan, I wouldn’t recommend putting coral skeletons in a freshwater tank. They are mostly calcium carbonate and would affect the pH and hardness of the aquarium. If you like the look of corals for your freshwater tank, I would recommend getting artificial ornaments instead.

  94. avatar

    Thank you so much. 🙂

  95. avatar

    Hello. A few days ago I bought a polyester resin ornament painted in part with epoxy paints made by a company that makes artificial reef ornaments. I was told to leave the ornament in water with some chlorine and salt to cure it. After that I changed the water and added a dechlorinator. Then I noticed some areas of the resin changed color and those smell like thinner and the ornament makes the water have a different strange smell. How can I get rid of the smell and make the ornament safe for a saltwater aquarium? Thank you.

  96. avatar

    Hello Arturo, That doesn’t sound like something I would recommend adding to a tank given the smell and change to the integrity of the paint; it doesn’t sound safe for aquarium use to me. I would recommend contacting that manufacturer that you purchased it from to see if they have any solutions for you.

  97. avatar

    I’m going to change some of the colors on the artificial reef ornament using acrylic paints. I have been doing some research and it appears that sealing the ornament with clear epoxy resin would be safe and inert. Do you believe the epoxy resin is a safe choice to seal the ornament? Regards.

  98. avatar

    Hello Arturo, I’ve conferred with one of the other marine biologists on this as well. The epoxy resin should be safe as long as it completely cures; you’ll want to follow the manufacturer’s instructions very closely before adding it to your aquarium. Resins like this do have a pretty strong odor but are safe as long as they are cured. The acrylic paint should be fine as long as it completely dries before you coat it with the resin. I would certainly recommend keeping carbon in your filter to help remove any chemicals or residue that may have possibly leeched into the water, especially given the problems that you’ve been seeing already.

  99. avatar

    Hi I made some artificial flower arrangements and used 100% silicone from a hardware store. Seems to stink. I have them soaking in water right now but is it ok to use them in my tank.

  100. avatar

    Hello Amy, The silicone should be safe as long as it has been fully cured and does not have any additives or chemicals like mildew-killers or other algacides. You will also want to monitor the plants and make sure they are safe; plants from a craft store for example may not be safe for aquariums depending on the type of paint or dye that was used.

  101. avatar

    Hello! Soon I am going to be getting a 25 gal aquarium for a betta fish and several corydoras and I’m very excited to decorate it. My father recently came back from Germany with a model of the Brandenburg Gate ( http://onlineshop.smile-berlin.com/de/product?info=1653 ) and I’ve read that polyresin figures are ok for aquariums, but I can’t really tell if it actually is polyresin and I’d really like to use it in my tank. Could it be alright or should i cover it in a sealant or even just not use it? Thank you!

  102. avatar

    Hello Ender, Have you tried contacting that vendor to find out what it is made from? I don’t see any info on that site about the materials but it looks to be polyresin based on the appearance and “poly” in the description. It would probably be safe but I would still recommend testing it underwater for awhile before adding it to the tank with fish, especially since its a small tank. It is a great little figurine though, should look great in the tank if it works out for you!

  103. avatar

    I have a 3 gallon fishtank that I bought about 2 years ago. While looking for decorations, I overlooked the large tube that ran straight through the middle of the cylinder shaped tank and bought a medium sized volcano to go there. When I got home my mom helped me come up with an idea of how to still use the volcano in the tank. We filed down the inside of the Volano hole so that the filter tube fit right down the middle of it. We did not seal the volcano and I believe that is the reason that my first and last 7 fish, including 1 beautiful teal male beta and 6 neon tetras, have died. I cleaned out the tank after the last few fish died and it has sat clean, but full of the decorations for about a year and a half. I have heard of a way to seal plastic involving olive oil. Can you tell me anything about that or do I have to go buy a special sealant from a pet store?

  104. avatar

    Hello Elara, I have never heard of sealing plastic with olive oil. Was this volcano an aquarium ornament to begin with or some other type of decoration? If it was an ornament, it shouldn’t have any effect on the water quality, even if it was filed. Even broken ornaments are fine to use as long as they don’t have sharp edges. You can seal the edges with clear enamel paint or even nail polish if its a small area; you’ll just want to make sure it is completely dried before putting it back into the aquarium.

    Very small tanks can be very tricky, especially with sensitive tropical fish like Neon Tetras and there could be a number of other factors as to why your fish aren’t surviving. You can certainly call and have a discussion with any of our Fish Room staff about your tank to help it be more successful.

  105. avatar

    I glued small rocks with aquarium sealant for beta cave but after 24 hrs the glue was not dry??? Why can’t it bond?

  106. avatar

    Hello annabelle, Aquarium sealants typically take 24 hours to dry and up to 48 hours to cure completely but humid conditions can make that take longer. If any of the surfaces were wet, that can also prevent it from curing. All sealants vary so I would recommend reading and following the instructions on the one you used very carefully. Many companies also have customer service helplines if you are having trouble with their product.

  107. avatar

    Hello! I’ve been really interested in arts and crafts lately and was wondering if a resin project would be safe in a fresh water tank? It usually takes 12+ hours to dry, there’s no paint or glues on it. Just want to know if it’s safe, thank you!!

  108. avatar

    Hi Jc. You can look for resins that are food-safe to be on the safe side, but most resins should be safe after they are fully cured.

  109. avatar

    I’m trying desperately to find some fish safe bottle caps (like beer bottle shaped), for my Fallout 3 themed tank, I can only find caps are made in Ecuador and China from shiny steel, they are lead and nickel safe… I’m guessing that any form of metal is a no no even if it was coated in silicone?

    Really need to find something like these http://www.ebay.co.uk/itm/Bargain-packs-of-flat-COLOURED-bottle-caps-and-epoxy-domes-dots-/221301805773?pt=UK_Crafts_Other_Crafts_EH&var=520184065743&hash=item33869d92cd

    Can anyone help me find something that would be fish safe?!

  110. avatar

    Hi BH, It is possible to coat an object in silicone or acrylic sealant but it is risky with metal; if any moisture can get to the metal, it may start to rust or corrode and affect the tank. I wouldn’t recommend it. Have you tried looking in craft stores or even party supply stores for plastic caps? Check around party favors or kids’ crafts and you might get lucky; I remember seeing some plastic soda can tabs in a craft store just a couple days ago. Depending on the look you are going for and how you’d like to use the caps (sorry, I don’t know much about Fallout 3), you could try using them on the outside of the tank – either on the front of the glass or as a background. You could also try filling a glass jar like this one with your caps and sealing the lid shut with silicone.

  111. avatar

    I bought a decoration from Petco designed for an aquarium. After a couple days it reeked and made the water smell horribly. I removed it and let it sit in water for a week. I was about to put in my tank but decided to test what chemicals could make it smell. Turns out the bacteria safe start began to make it smell again. Any suggestions or could you recommend other decorations this won’t happen with.

  112. avatar

    Hello PW, Is it the ornament itself that is smelling bad or the water? Can you give some more info about your tank – size, how long it has been set up, the fish in it, the levels (actual values) of pH, ammonia, nitrite and nitrate, etc.? You mention “bacteria safe start”…is this what you are smelling or is it something else? A lot of bacteria supplements for new aquariums can have a strong smell, as can aquarium that are heavily stocked or have a water quality issue. An ornament that is starting to smell would be very unusual, but a new and heavily stocked aquarium might not be. I would recommend calling in and having a discussion with someone in our fishroom to help you get to the bottom of the problem. You can reach the fishroom staff at 717-299-5691, option 7 or 888-842-8738.

  113. avatar


    I have a piece of glazed ceramic pottery that was made in a high school art class. If I cover it in aquarium sealant, would it be safe to use in my tank as an ordament?


  114. avatar

    Hello Nancy, I would recommend checking with the art department to see if it is a glaze that is safe for food use. If it is, it is probably safe for use in your aquarium. If you have any pottery studios near you, you can also check with them to see if they can glaze and fire your piece with a clear glaze that is safe for use with food and in water to make it safe. Most aquarium sealants won’t be clear or thin enough to coat a piece as an ornament but you can look for a clear enamel to coat your piece.

  115. avatar

    Ceramic mugs will be safe right? Any specifications for mugs would be nice to know, thx

  116. avatar

    P.s. I haven’t read any posts except for the first 2 (on this chat atleast)

  117. avatar

    Hello Msm, Yes, coffee mugs are usually safe. You can check out the second paragraph under “Think Outside the Box” for tips regarding mugs and my follow-up blog, Aquarium Decoration Ideas – Fish Bowl and DIY, for a sample aquarium I set up using a coffee mug. As a rule of thumb, if it is dishwasher safe, it is probably safe for use in an aquarium. Avoid any mugs that have delicate artistic glazes or that aren’t fully glazed and fired.

  118. avatar

    I am setting up a freshwater aquarium at work. We have large shark jaws (real) that we want to put in there. What can I coat them with to make it safe for the aquarium and the jaws? So far from what I have researched says marine epoxy. Do you know anything about coating things like this, or starfish etc..

  119. avatar

    Hi Erin,
    Very generally, acrylic sealants can be used to coat an object to use in a tank. Using anything organic is risky though. Even a small crack or hole in the sealant will let water in over time and will get bigger and bigger. Most jaws that are sold in sea shell shops and as souvenirs have been bleached to make them whiter and adding them to an aquarium could release any chemicals they’ve soaked up into the water. Depending on the water parameters, they can also start to dissolve and release calcium into the water which would affect the pH and hardness. Other animals like starfish would almost certainly start to decompose once they get exposed to any moisture. A safer approach if you would like the look of saltwater animals in a freshwater tank would be to go with ornaments. We have some very realistic-looking artificial coral ornaments and you may be able to find a resin shark jaw ornaments as well (we’ve carried some in the past that we’ve unfortunately since discontinued).

  120. avatar

    Hi! I am looking to get a pokemon ball for my aquarium that will house an axolotl. I have found a man who makes 8cm ones but was unsure on the safety issues with the materials it is made out of. He said that it is made out of chrome plated, brass and that they would seal the two halves together with hot glue. One individual that I have spoken to about this already, said that as long as it is sealed well that it should be fine for my aquarium. Can you give me your own opinion as well before I do this? I don’t want to hurt my little guy.

    Thank you!

  121. avatar

    Hi Samantha, I wouldn’t recommend using anything metal with water. Chrome will rust and brass will corrode, both of which will affect the water quality. While you can coat it with a clear enamel or another sealer, if any moisture at all gets beneath that coating through a tiny crack or pinhole, it will affect the water. A safer bet if you’d still like a Pokemon ball ornament would be a colored plastic one…you’d want to look for one that is strictly colored plastic without any decals or coating.

  122. avatar

    Hi! I take a pottery class, and would love to make some stuff for my tank. I made a cave with food-safe glaze, but one side is unglazed bisque. Though it was fired in a professional kiln, I worry that the clay will somehow soften or hurt my guppies. Is it safe?

  123. avatar

    Haley, the unglazed pottery should be safe once fired, I don’t think it can soften. The only concern that comes to mind is that it could affect the pH of the water depending on the properties of the clay. You could soak the pottery in clean fresh water for a few weeks to allow for anything to leach out of the piece, and you can test the pH of the water that it has soaked in to see if there are any changes.

  124. avatar

    Hi, a relative gave us his aquarium and all supplies. A starfish was in there and I assumed it was a bought decoration. Apparently it was real as it is now disintegrating. Any ideas on how to get it out? It is now bendable and breaks apart if I touch it. However this may be the answer to why we had 30+ baby guppies and now are down to 4. 🙁
    Thank you for all your help!

  125. avatar

    Hi Margie, If the starfish is breaking apart and disintegrating, it unfortunately sounds like it wasn’t an ornament or isn’t safe in some way. I’d get it out of there as soon as possible, test your water quality and go from there to help out your remaining fish. If you need any further help, feel free to give us a call and we can help you figure out your gameplan moving forward.

  126. avatar

    Hi! I have three smooth white pebbles and I’m wanting to make a snow man out of them. I want to use a hot glue gun to attach it together. Is this safe for a fresh water tank with a yabby in it? Thanks!

  127. avatar

    Hi Jack, Yes, a hot glue gun would be fine for creating your snowman. Glad your yabby is getting in the holiday spirit too!

  128. avatar

    I’m looking for a fish tank ornament that can be personalized with a picture. I was hoping for a scuba diver with my kiddos faces on them. Do you think it would possible to make something like this? Do you know of a place that sells something like this?

  129. avatar

    Hi Elizabeth, I don’t know of any companies that custom-make ornaments like that or a way to safely and permanently (and safely) attach a picture to an existing one. Instead of an ornament, you could do a custom background. There are websites that allow you to insert a face into an image to create your own picture (Face-in-Hole comes to mind as one I’ve personally used before). Depending on the tank size, you could either cut out the diver or use the whole image as your background. Good quality photo paper will usually hold up just fine as long as it doesn’t get very wet, or you can have it laminated to make it extra durable.

  130. avatar

    Hello. Today I got plastic plants especially designed for aquariums. They were bent and I tried to straighten them, since I could not, I used a hair drier to do that and while they were warm the plastic smell intensified and then went back to normal. Are these plants safe to use in my marine aquarium after heating them? Regards.

  131. avatar

    Hello Arturo, They should be fine. The smell was likely just the heated and melting plastic from your hair dryer and the plants should be fine again once they cool.

  132. avatar

    If I were to paint acrylic and cover the entire thing with an aquarium safe sealant, would it be safe?

  133. avatar

    Hello Kim, It would depend upon the type of paint. Even covered with another sealant, small cracks or crazing can allow moisture underneath the sealant. I would recommend reading over part three of this series, , which covers that topic more specifically.

  134. avatar

    I heard Placos like wood to nibble on. I have an 800 gal concrete goldfish pond in my back yard. In it I have a couple pieces of small driftwood for the frogs when they show up. I broke off a smaller piece and am boiling it as I write. Wondering if it will be ok to put it in mt 5 gal fresh water aquarium. I have the one bushy nose and 3 platy. Just got over the mama eats her babies trauma last night. I knew she was going to give birth at any minute but since we don’t want any more fish I endured. Btw would the females be ok w/o a male? I see enough of the spawning with my goldfish. I do love my small indoor tank to get me through the winter. One more thing. I have some canned peas for him and some zucchini. I am assuming I should cook and cool it before offering. I feed algae wafers at night about 3 times a week as it is a new tank. Thanks for any help you can offer

  135. avatar

    Hello Brenda, Some plecos will chew on driftwood as part of their diet but the ones commonly referred to as “Bushynose Plecos” are not part of that group and don’t need driftwood in their tank. I would use extreme caution in putting anything from an outdoor pond into an aquarium, especially one that small, since there’s really no way to be sure that no pesticides, fertilizers or other chemicals haven’t gotten into the wood. Fresh aquarium-specific driftwood would be safer but still isn’t necessary. If you try adding the wood you have from your outdoor pond, I would make certain that your filter has fresh carbon and that the carbon is being changed regularly so it can absorb out any toxins that may be in the water. Male and female Platies are fine together but will of course continue to breed. For any vegetables you are using to feed, make sure they are not treated or seasoned in any way and are free from preservatives or other chemicals. You don’t have to cook it but can to soften it up if you’d like.

  136. avatar

    I’ve set up a tank for a school of pearlscales with marbles, glass & acrylic melted marble type, and acrylic diamonds partial substrate. Along with such, I’ve placed several lead glass crystal meditation balls and some crystal whiskey glasses with marble/diamond substrate to hold the plants. No paint, all clear, except a 3″ etched globe meditation globe. When checking on lead leeching I found test show some, but in juice/wine/acidic liquids not cool water. I found one web post that was actually a beta site that claimed it to be bad. I was wondering if you would be able to provide any additional info? Thx

    I know… between the plant nibbles, waste, etc. This could be high maintenance even with the vacuum, but it sure is bright. Crushed ice-looking everywhere, then a pearlscale passes a ball… interesting.

    Thx, again

  137. avatar

    I wouldn’t recommend using anything that is going to leech lead or other materials into your water. I assume that you have Pearlscale Goldfish, which can produce a lot of ammonia and lead to low pH which is acidic as you mentioned that you have seen causing leeching. Keep an eye on the colored marbles too; I have had a colored glass diamond in a betta setup before which had a glaze that was able to be scrapped off once it was in the water for awhile.

  138. avatar

    Is it safe to put legos In with fish

  139. avatar

    Hi, I have found a terracotta pot under the house and it is full of dirt. It also has Acrylic Paint on it. I spent all after noon cleaning the dirt off it and trying to scrub the paint off too. I got most of the paint off. Will a little bit of Acrylic Paint effect the water? Thanks!

  140. avatar

    Hello Coolman, I would avoid Legos with decals on them but otherwise, plain plastic Legos would be safe. If you have any pieces small enough for your fish to eat if they become separately, you may want to seal or glue them in place.

  141. avatar

    Hello Jack, A bit of acrylic paint would be safe but I would be cautious using pots that were found, especially outside, since it would be impossible to tell if any chemicals may have leeched into the pottery.

  142. avatar

    Hiya, just wondering if anyone could give me some help…. I love the look of this tank: http://2.bp.blogspot.com/_JYCMRJbidPQ/TQ3rKiD0a6I/AAAAAAAAAXw/2lazX-74ogw/s1600/fts.jpg and have read on their blog that they used dried bamboo sticks which eventually became rotten over time, I was just wondering if anyone could help me find anywhere that would do plastic / ceramic sticks or give any advice on how I could recreate the bamboo look in my own tank?

  143. avatar

    Hi Bee, Happy to help. Bamboo will certainly decompose just like any other wood over time. I wasn’t able to locate any artificial bamboo stalks with a quick web search but there are ways to recreate the look without them. My first response would be what it looks like they recommend on that blog, to use bamboo sticks and replace them over time. That blog says they noticed their sticks starting to decompose after six months or so; I would certainly replace them before they get to that point. If you would like to recreate the vertical lines of the bamboo without using actual bamboo, you could use stalks of another artificial plant like this Club Moss or Corkscrew Val. Plants like these are usually made in bunches but you can deconstruct the plant by taking individual stalks out of the base or cut them near the bottom and plant the stalks individually like the bamboo sticks in that photo. You may have to create a new base to keep the stalk down, but that is easy to do by gluing them to a rock or creating an epoxy base to bury in the substrate.

    Another way to use the bamboo would be to keep it dry. You could use a thin glass tube tall enough to reach above the water levels like these test tubes to hold the stalks of bamboo. A little sand in the bottom can help them stay upright in the tube. You could also use a larger vase inside of the tank in the same way to create a little dry “garden” in the center of the tank. As long as the top of the vase is above the water level, it’ll stay dry. The look is a bit less organic than your inspiration photo but the little dry “bubble” inside the tank can still have a very unique look.

    An easy solution is also of course to use the look you want as a background on the tank, especially for a smaller tank. If you find an image you like, you can print it on photo paper or have it laminated and create your own custom bamboo background. Try searching for images online; computer wallpapers make good tank backgrounds and I found a lot that are similar to the vibe of that tank by searching for “bamboo garden wallpaper”. Good luck!

  144. avatar

    Hello. I’m trying to find an object that will be safe to use as a small cave for one of my bettas (currently he is jamming his head under a river rock to nap). I can’t seem to find anything commercially made that is completely smooth. (He is a clumsy betta.) I could use aquarium sealant and build a little cave out of river rocks, but I read somewhere that someone had used an old tea cup for this purpose, which I think is adorable. So I’ve been searching for an appropriate cup. They are food safe, of course, and are meant to withstand hot tea. But most are made of porcelain (bone china) and have gilt edging or details. This is food-safe metal that is unlikely to corrode (gold doesn’t). But I’m still worried. Is a cup like this likely to be safe?

  145. avatar

    Hi nonobaddog, Most mugs and similar porcelain is safe – you can check out a sample aquarium with a coffee mug on the followup to this blog – but decorative finishes can be a problem. As a general rule, look for a dishwasher-safe piece. If it isn’t dishwasher safe, it is probably a more decorative finish that might not hold up as well underwater and in aquarium conditions. Try looking at craft stores or homegoods stores…I’ve even seen some nice plain pieces that would be appropriate at Walmart and Pier One! It is an adorable idea though and can be a cute cave for your little klutzy fish. 🙂

  146. avatar

    My spouse and I absolutely love your blog and find many of your post’s to be what precisely I’m
    looking for. Do you offer guest writers to write content to suit your needs?
    I wouldn’t mind creating a post or elaborating on some
    of the subjects you write in relation to here. Again, awesome blog!

  147. avatar

    Hi, thanks for commenting. We do accept guest blog submissions. You can forward them to blogs@thatpetplace.com. Thanks!

  148. avatar
    Joseph Cervantes

    Hi, Iam thinking outside the box and want to set up my 55 gal. with an Aztec theme. My question is for the center bottom piece buried under some gravel I want to place a large Aztec or Mayan Calander. I need to know what type of material is safe for using underwater . I tried the pottery and clay and in time faded away and broke in parts. now I was thinking of brass or metal plated is this safe for my tropical fish and plants . also please inform me on what type of small statues are safe to place around the aquarium. If I can complete this project this will be a great looking aquarium. I am looking forward to your expertise advise. thank you and ready to send in my photos with your help.

  149. avatar

    Hello I know you said using painted figures is not recommended, but I am making an action figure display in a tank with no fish. Is there any type of protectant they sell that I can cover figures with to make them last in a tank thanks

  150. avatar

    Hello Joseph, I would recommend taking a look at our third blog in this series, “More Decoration DIY: Materials and Aquarium Suitability”. I do not recommend using metal of any kind but many plastics, ceramics, potteries and glass are safe. If you can’t find a Mayan calendar that will hold up underwater for you, you can also try using a decal or printed background outside of the tank like I did in part 2, “Aquarium Decoration Ideas – Fish Bowl Designs & DIY”. We look forward to seeing your photos of the finished tank!

  151. avatar

    Hello Javier, Painted figures and action figures can be safe. In part two of this series, “Aquarium Decoration Ideas – Fish Bowl Designs & DIY“, we discussed some action figures that we’ve used in tanks here including a nomadic Aquaman that was in our planted canyon last I saw and a Master Chief that used to live in our large cylinder display. The key is using figures that do not have decals, stickers or metal parts. You can use clear enamels or even clear nail polish to cover up small spots but if the whole thing is questionable, it is best to leave it out. Check out all three parts of this blog series for more specific information on what materials and paints are safe to use or best avoided.
    This Aquaman has been moving around our store for years now.

  152. avatar

    I recently created clay ornaments and painted them and coated them in epoxy resin and let them cure for a week and as soon as submerged in water, they turned white and splotchy. Any info on how to fix or reverse this will be much appreciated!

  153. avatar

    Hi Christopher, I don’t know that that is something that you would be able to fix or reverse. My guess based on your description would be that the epoxy resin separated from the clay ornament…something similar happened when I coated a hockey puck in enamel nail polish to preserve the image printed on it. What kind of clay was it? Was it fired or glazed? What kind of paint did you use? How soon after painting it did you coat it with the resin? Some step in that process or material you used may not have been compatible with being submerged and a different material may work better for you next time.

  154. avatar

    I like to frequent this “Paint your own pottery” place, where you pick out pre-made cups, bowls, sculptures, ect. You paint it, then they glaze and fire it for you. I was wondering if these items are safe for a freshwater tank. They have a betta bowl with a small sculpture, but I love clown loaches, and due to their high sensitivity, I really want professional advise first. I think it would be amazing to paint something specifically for my tank, seeing as I have had my fish get stuck in store-bought decor before. (And then had to rip is apart with my bare hands) I’m not sure what kind of glaze they use, but the owner is sweet and couldn’t tell me weather or not her glaze is that formidable against the weathering of a bigger more sensitive tank. Are there specific brands that are ok, or are there just certain things I should avoid like lead. (Doubt her’s have led, it’s a food safe glaze)

  155. avatar

    Hi Lexie, I worked at a paint-your-own-pottery place in college so I know exactly what you are referring to. Definitely avoid anything lead-based or decorative glazes that aren’t food-safe. Food-safe pieces may be safe, but I would recommend sticking to pieces that are dishwasher-safe since these usually hold up better to the water conditions (heat, pH, etc) that being constantly submerged in an aquarium would submit them too. Your studio should be able to tell you if their glasses and pieces are dishwasher-safe or not. Also, be sure to inspect the pieces very closely to make sure there aren’t any small spots that may have been missed by the glaze like in small corners or where the pieces were held up on the small stands in the kiln. I would definitely have the entire piece sealed with a clear glass if the studio doesn’t do so already. You may even want to have them re-glazed with a second clear coat after the first firing. I wouldn’t know what specific brands would be safer. If the studio owner isn’t able to provide information about her glazes, I would see if she is able to contact or give you contact information to where she gets her glazes from and check with them directly. Of course, “when in doubt, leave it out.” Good luck!

  156. avatar

    Hi Eileen,

    Thank you so much! The owner is very nice, and seems very accommodating. I really hope that I can get something in there that my fish won’t get stuck in!

  157. avatar

    Good luck! Try vases, or using plates, platters or tiles to make caves. Unfired bisque isnt too hard to cut with a dremel or saw; they may be able to cut the botton off a vase to make a tunnel for you. Have fun, be creative, and show us what you come up with!

  158. avatar

    I just found your site, and I was wondering, what is the best way to add writing to an aquarium decoration I bought from the store?
    Thank you!

  159. avatar

    Hi Ilsa, That would depend on the surface of the ornament, but I’d recommend enamel paint. We’ve had success here with it but it tends to lose color after awhile. You can use nail polish pens or enamel model paint and a fine paint brush from the craft store; just be sure the paint is COMPLETELY cured and dried before putting it into the aquarium.

  160. avatar

    Hi :),

    I just got done reading two of your blogs and all the comments and answers left on this one but didn’t see anything bout using ribbon or adhering crystals,beads…that sort of thing to decor so it is safe for my 40g freshwater fancy guppy (also may add ghost shrimp and the little catfish looking algae eaters) tank. I want to personalize to store bought aquarium decor skulls to represent me and my spouse. Is cloth safe? Anyway to seal it to make cloth more harder to hold shape and be safe? Oh I also have real drift wood and real moss (shape like hearts). Thank you for all your help!

  161. avatar

    Hi Stephanie, You can use glue to attach beads like those listed in Part 3 of this series. Most beads or crystals are probably safe as long as they aren’t glazed or painted with any finishes that will soften in the water; be sure to test the materials and keep a close eye on them once they are added. The cloth is tricker. It would certainly depend on the type of cloth and I would expect that it would grow algae and might not hold up in the long-term. I would recommend taking a look at artificial aquarium plants rather than ribbon. There are lots of colored plants available and you may be able to disassemble and cut apart some of the grassier plants for a ribbon-like look. The GloFish line especially has some brighter colors.

  162. avatar

    I just bought some purple barnacles at one of those tourist trap gift shops on the shore. I was wondering if the barnacles would be ok to put in my aquarium if I soaked them in warm water for a couple hours? They arent painted and they arent alive

  163. avatar

    Hi Sarah, That is difficult to say since it is impossible to tell what may have been done to the barnacles before you bought them like dyeing or bleaching. I personally wouldn’t take that risk. It would also depend on whether you have a freshwater or saltwater tank; barnacle shells would be fine in a saltwater tank but would affect the water chemistry of a freshwater tank.

  164. avatar

    I want to do a little mermaid fish tank but everything sold for fish tanks is really small. I was thinking the Disney bath toys would work but how could I weigh them down from floating? Put aquarium rocks inside and then seal it with super glue? Thanks!

  165. avatar

    Hi Liz, Putting rocks or sand or some other kind of weight inside the toy should certainly work for you. You could also work with the toy’s inclination to float and suspend it in the water with some fishing line tied to a weighted base of some kind that you could bury in the substrate. We’ve carried some jellyfish ornaments that use a similar approach.

  166. avatar

    I am trying to make a My little Pony themed thank but can’t find fish decor for it. I have rubber figures but they are painted. Can I use them in the tank if I put a coat of Silicone Sealant on them?

  167. avatar

    Hi Katie, I wouldn’t recommend it. You could try using a clear enamel paint but anytime you coat something that isn’t safe, there is a chance that any tiny cracks in the coat are going to allow moisture to seep in to the toy. How about going with some rainbow-colored plants and aquarium ornaments inside the tank and use a My Little Pony background or window clings on the outside? You could also try looking for some pool or bath toys that might be safer and more durable than the regular figures.

  168. avatar

    I’m setting up a 55 gal. discus tank. I have what looks to be an unglazed bisque castle made by Partylite as a tea light holder. How safe is it for an aquarium? Would painting it with silicone make it safe?

  169. avatar

    Hello Jenn, I would recommend contacting Partylite for more information on their materials and durability. As a general rule of thumb, if it is dishwasher-safe, it would likely be safe in your aquarium. I’ve had some Partylite pieces in the past and from that, I wouldn’t recommend putting it in your tank. Coating unsuitable pieces in silicone or enamel is risky and never guarantees that they will remain safe.

  170. avatar

    Hello… I work at a mechanic shop and im a fish lover the owner has been thinking of putting a fish tank in the shop and I would love to put it little toy cars like hot wheels in the tank could I put it in there itself or is it fine to use a clear silicone on it and put it in the tank after it drys?

  171. avatar

    Hello Savannah, The 3rd part of this blog, “More Decoration DIY: Materials and Aquarium Suitability” may be helpful to you. I do not recommend putting anything metal in the tank, coated or not. Any moisture that gets through that coating through small pores or cracks can reach the metal and cause corrotion and other issues. Plastic pieces, glass or pottery without delicate decorative glazes, rubber pieces like tires should be safe.

  172. avatar

    Hi there

    A friend of mine has been asking for help on making his fish tank look better and recently i came across a dassie skull which i would like to add to the fish tank. What would i need to do to ensure the skull does not affect the fish or fish tank?


  173. avatar

    Hi Rain, Adding anything organic like bone to a tank is very risky and I wouldn’t recommend it, especially for a found piece of unknown origin. If you found the skull somewhere, it is impossible to tell if it has been exposed to or absorbed any chemicals or other harmful materials to your tank. Also, depending on the type of tank and water parameters, the bone or any organic materials left in it may decompose and affect your water quality, especially in tanks with lower pH.

  174. avatar

    I am a hockey freak. I want to put a hockey puck in my 10 gallon fish tank.nwhat do you propose I do to make the puck fish safe?..

  175. avatar

    Hi Frank, As a fellow hockey freak, I have done the same thing! Rubber pucks in themselves are safe since rubber is inert and shouldn’t affect the water quality. Any decals on the puck may not hold up in the water however, depending on the water chemistry. I’ve tried coating a puck in clear enamel to protect a decal but the enamel separated from the puck and didn’t work as I hoped. I would recommend using a plain, clean puck or, if you use any pucks with decals or any decorations, monitor it closely to make sure it isn’t affected by the water chemistry.

  176. avatar


    I love your advise but I just wanted to askwhat kind of clay is safe to use in saltwater aquariums. I am trying to make a replica of Iron Man’s Mark VII mask. Also, if they are, what glazes are safe for aquariums and fish?

    If glazes aren’t safe, can you tell me if there are any alternatives that are relatively inexpensive?

    Thanks so much!

  177. avatar

    Hi Cheyenne, Ornaments like that are much tougher in saltwater aquariums because they have a lot more organisms that are encrusting (like coralline algaes) or boring (meaning digging or drilling like some snails and worms, not as in the excitement factor!). Fired pottery like ceramics are generally safe but I would stay away from polymer clays like the Sculpey clays we discussed on here in other comments. Glazes that are dishwasher safe are generally aquarium safe as we’ve discussed before but when in doubt, check with the manufacturer. Enamel paints like those in nailpolishes and for models are usually safe as well but in our experience in using them in some of our systems, the color tends to fade over time with the water conditions and lighting.

    Depending on your crafting skills and since that helmet is a fairly smooth and simple shape, you could try molding it or sculpting it out of an aquarium epoxy putty like these. Those putties can take some practice to use but they can usually be found in a neutral stony grey and in coralline-algae purple. Not exactly Iron Man red-and-gold but close!

  178. avatar

    Hello Eileen. I hope it is OK to ask you the following in this blog and thank you for all the help regarding resin and plastic ornaments. Now I have a question about the substrate. I want to add to my marine aquarium a yellow “coris” wrasse and I have an aragonite substrate in the neighborhood of 1.5 to 2 mm grain size. I have been doing some research on the web about the right kind of substrate for that wrasse. Some places mention it needs fine sand to dive into to sleep and other places state it doesn’t need sand at all. Do you believe the substrate I have will be good enough for that fish to dive into? Happy Holidays.

  179. avatar

    Hello Arturo, I’m assuming that the wrasse you are referring to is the Canary Wrasse? These wrasses do much better with substrate to bury into when threatened and to graze food like copepods from. Fine sand with smooth edges is much better for them and their delicate skin than coarse substrates but larger wrasses should be fine with 1.5-2mm grains as long as they don’t have sharp or jagged edges.

  180. avatar

    Is it safe to use a cupboard organizer in a turtle tank? It is steel coated with epoxy….I need a larger basking area and thought this would enable me to make a large basking area while leaving room for swimming….I would of course use slate on top for my turtles to lie on.

  181. avatar

    Hi Tonia, I wouldn’t recommend using anything with metal in water. If there is even a small crack in the epoxy coating, water can seep in and reach the metal, causing it to start to rust. I would recommend contacting our Reptile Room staff at 717-299-5691 for some recommendations on a setup that might work for you. You can also take a look at our That Reptile Blog for more ideas basking dock ideas specifically for turtles.

  182. avatar

    I can use POP ( plaster of Paris) ornaments to my freshwater fish tank or not?

  183. avatar

    Hello Sourav, Plaster of Paris is not safe in aquariums. It has a carbonate base and will dissolve over time and will affect the water chemistry.

  184. avatar

    nice article, thanks

  185. avatar

    hello i have this vision of creating different levels or platforms in my barebottom tank but i do not know where to buy the items or if they even exist? I am searching for something that is made out of acrylic or a transparent material.
    (similar to these)


    the only thing that i have found so far that can create different levels is an item called “hide away cubes”, but this item is not transparent and not a big enough surface.

    I have even tried to search for a stick on “floating shelf” type of decor for the tank but i cant seem to find anything:(

    am i just dreaming too big or can someone tell me where to find what i am looking for?


  186. avatar

    Hi Faizah, I can’t view your links but acrylic is generally a safe material, as are most other plastics. You could also look at frag racks like this straight rack or this corner rack, both from the Eshopps brand. Another option would be something like these plastic habitats, on their side or upside down and without the lid. These ideas would of course depend on the size of your tank and the shelves you are looking for as well as what you are looking to put on them. Hope that helps!

  187. avatar

    Could I put a matchbox car in a basic Beta tank?

  188. avatar

    Hi Rachel, Metal doesn’t do well in water. It is best to stay away from anything with metal parts.

  189. avatar

    Hello I have been searching for an answer to this and although I have seen people ask the same question no one has answered it. I have really liked the Schleich toys. They have so many types of them and have been really wanting to try and put them in my themed tanks. A 55 gallon and a 29 gallon. I would love to know if these would be safe or would I need to cover them with something. I just worry about my fish. Had a few tragities and we are getting more into expensive fish that are not as easy to find and replace. Any help would be great thank you.

  190. avatar

    Hello Tasha, The best place to get an answer for that question would be the manufacturer directly. I see on the website for the Schleich brand that they appear to use a high-grade plastic but I wouldn’t be able to speak to the durability of the coloring. Like we discussed in the 3 parts of this blog, it is always a good idea to test any new materials and keep an eye on them regularly for durability. It would of course depend on the types of fish that you have in with them and the water conditions, but I wouldn’t expect them to be very harmful…but I also wouldn’t know how well they could hold up. I would recommend contacting Schleich.

  191. avatar

    Hello, I have a 60 gallon fish tank with black substrate. I absolutely love zombies and the walking dead, and it is extremely hard to find zombie theme fish tank decorations. So I bought 12 6″ tall walking dead zombie action figures off of amazon. So I’m wondering if I can coat them in aquarium silicone and put them in my fish tank and it be safe for my fish. I have a placo, 3 reed fish, and 4 angel fish in my tank and I’m wanting to “zombiefy” my tank.lol so I’m wondering if I could coat them in aquarium silicone and it b safe for my fish and not kill them because they weren’t cheap.lol

  192. avatar

    Hi James, The should be safe as long as the figures don’t have any metal parts in them (in the joints, for example). If they have any metal at all, I wouldn’t recommend adding them to your tank, even if they are coated. If you would like to try a protective coating, I would recommend a few coats of a clear enamel over aquarium silicone…it will be clearer and thinner than silicone. If you browse up through the other comments on this post, you can see an example of an action figure that has been moving around in tanks in our Fish Room for a few years now. Another option for you if the figures don’t work out (or even if they do) is a zombie background. You can look for a zombie or Walking Dead poster that will cover the back of your tank or look for a graphic online (Google “zombie window”, for example) that you can have printed and laminated big enough to cover the back of the tank.

  193. avatar

    hey i have a 10 gallon tank and i have a mold of my hand that i got from a wax museum. assuming that it would be safe because they formed the wax around my hand but i dont know. it has blue, red and white wax on it. not sure of what type though.

  194. avatar

    Hi Joe, That is difficult to say. Wax tends to soften up underwater, especially if it warms up as well, so I would have doubts about how well it might last. The dye that was used to color it might leach into the water as well, especially if it begins to dissolve or soften. You could try soaking it in a bucket of water (preferably with the same water conditions as your tank, pH and temperature especially) to see how well it last before adding it to your tank but I would recommend leaving it on the shelf instead of trying it in the aquarium.

  195. avatar

    Hi Eileen,
    Ived read through many of the questions above but don’t think I have found an answer just yet. I’m building a 30 gallon zombie theme aquarium. I bought some plastic figurines. From your answers I have read that plastic is safe for the most part. I know that salt water is harsh and I wanted to know which brand or exact sealant you can recommend for me to use on these figures? I want to preserve them the best I can in their soon to be harsh environment. Please tell me what brands is best to use to seal them.

  196. avatar

    Hi Wendy, Clear nailpolish or a few coats of spray enamel will help protect your figurines. Saltwater tanks can be tricky since any ornaments tend to get encrusted with coralline and other algae but that may help your zombie look! (check out the artwork by Jason deCaires Taylor to see what I mean…he does some amazing underwater sculptures). You may have to scrub and re-treat your figurines over time if you would like to keep your zombies in “pristine” undead condition.

  197. avatar

    Hi there,
    Any recommendations on using cold cast resin figurines? I’m thinking of coating it is. Enamel clear coat, would that be okay for my saltwater aquarium?

  198. avatar

    Hi Wendy, Most aquarium ornaments are made of poly resins so you should be safe. As we discussed before, spray enamel will help protect the ornament but it is difficult to keep any ornaments in saltwater aquariums clean because of all the encrusting algae and other organisms…that is a big reason why very few saltwater aquariums have ornaments over natural decorations like rockwork.

  199. avatar


    I just purchased a 55 gallon acrylic tank, and am wanting to decorate it with an Egyptian theme. I’ve found some objects already that are made for the aquarium, but some other objects that I need are just figurines made from resin, Poly-resin, but hand painted. Are they safe to use in my fresh water tanks? Is there anything I can do to protect my fish from the paint? Would the Epoxy sealant or the spray enamel work for these objects? What sealant do you suggest in the event the paint comes off?

  200. avatar

    Hello Dee, Without knowing what kind of paint was used in the figurines, I really can’t say if they will be safe or not. You can try coating them with several coats of clear spray enamel to protect them but you may want to try contacting the artist or manufacturer to see if you can determine what kind of paint they were handpainted with.

  201. avatar

    Hello.This post was really motivating, particularly since I was searching for thoughts on this issue last Thursday.

  202. avatar

    Hello Eileen: thank you for your reply. I ended up coating the objects with enamel and letting them cure. I read in earlier post where you wrote coating them with enamel is the way to go, so I did that. I just saw your answer today. I really enjoy this blog because I’m learning much more then I ever knew about maintaining an aquarium. Thanks so much!

  203. avatar

    You’re welcome, Dee…happy to help!

  204. avatar

    I have a small bridget ornament I bought and it says it is made of stained resin. would this be safe to use

  205. avatar

    Hello Laken, If it was purchased as an aquarium ornament, it should be fine for your tank.

  206. avatar

    Hello Eileen!!

    I noticed that some of my aquarium objects were feeling a bit slimy, I tested my water and everything was fine, normal levels. Is this normal? Also what can I feed my algae eaters besides algae chips when there isn’t a lot of algae in the tank. They won’t eat those chips. In fact those chips being left in the water started to raise my ammonium levels, and grew something on them that looked like cotton. I found some stuck to my strainer for the pump. Because of that I did a water change and cleaned some gravel. Can you suggest something else to feed them if they refuse to eat the chips. Or, are they not eating the chips because it’s enough algae in the tank? I’m confused. I’ve had tanks before and used algae chips, but the algae eaters ate the chips, the two I have in this tank doesn’t.

  207. avatar

    Hi Dee, A slimy coating usually just means the tank is dirty or there is a lot of organic waste in it. When you say your water levels were “normal”, what were the actual values? How often do you do water changes? How large is the tank and what all is in it? Also, what type of algae eaters do you have? Some fish that people know as “algae eaters” like plecos aren’t actually algae-eaters at all or algae isn’t a big part of their diet so those algae chips you mentioned might not be the right food for them.

  208. avatar

    Hello Eileen:

    I did have a type of slimy coating until I added a little water a week or so ago. But on Saturday I cleaned the water, removed 50% of the water, cleaned the gravel, added new water with a water conditioner and I don’t feel the slime anymore. I haven’t tested the water since this past Saturday, I’m planning to check it tonight. I’ve really only had the tank for a little over a month, and the fish inside for less than three weeks. My test results from Saturday 2/25/17 before the water change were, PH 7.6, High PH, 7-4, Ammonia, 1.0ppm, Nitrite, 0ppm, Nitrate, 0ppm. I had also tested the water on 2/23/17 and the ammonia was at 0.50ppm. and on 2/17/17 and the PH was 7.6, High PH, 7.4, Ammonia, 0.25ppm, Nitrite, 0ppm, Nitrate, 0ppm.The only thing that has been a bit high is the ammonia. So when I saw that it was rising, I cleaned those algae chips out of the tank and off of the strainer, and then cleaned the gravel and of course while doing that water drained from the tank. I added API water conditioner to the tank for the new water. After I test the tank, if the ammonia is still over oppm I have some live bacteria from “Special Blend” that I used during cycling. It can be used to maintain as well. I’m not sure the species of these two algae eaters, they’re slim and orange. The person at Petland who tends to me told me they go in a glofFsh tank. That’s where he had them. I definitely have algae in the tank because as I was cleaning the glass on the top inside of the tank, with a special cloth for acrylic tanks, there was some greenish black stuff on the cloths. The tank and water looks crystal clear, no visible algae on the glass, but after seeing it on the cloth, I know it’s there. The algae eaters are obviously getting plenty to eat because they never touched those algae chips. They’re feasting on the gravel, pebbles, ornaments and glass. They could care less about those algae chips. I was just worried because I didn’t know at first if there would be enough algae for them in the tank. I have a 55 Gallon tank and Tetra’s. The majority are GloFish. I only have four regular Tetra’s and two algae eaters. The rest are GloFish. My tank is 24 inches deep, 48 Long and 13 wide. It’s a pretty big tank, and I didn’t over crowd it. I think at the most I have about 35 fish. Thank you for your reply Eileen, you’re awesome!!

  209. avatar

    Oh Wow Eileen, I just looked at an image of the Plecos algae eater, and those are the algae eaters I’ve always used in prior fish tanks. They kept the glass clean, and they did eat the algae chips from another brand. They loved them. I’m very surprised that the Plecos aren’t really algae eaters, because they were always sucking on the glass and ornaments in my tank. They kept my glass and ornaments very clean of algae. If they aren’t really algae eaters then why are they being sold as? And why do they behave as the algae eaters I have in my tank right now? This is very surprising.

  210. avatar

    Hi Dee, It sounds like there are a few issues going on here. I’m going to send you an email to avoid a super long reply here in the comments so if you don’t see that message soon, let me know!

  211. avatar

    Hello I bought some large glass marbles at hobby lobby to decorate the bottom of my freshwater fish tank, the label says they may contain a water soluble surface coating. Is this safe for fish? I also wondered about the marbles fading but it’s not saltwater. Thanks

  212. avatar

    Hello Cassie, If they are labelled as having a water soluble coating, then they wouldn’t be safe underwater in an aquarium. I would look for another material. Colored glass (not glass with a colored coating) would usually be safe, and marble-type stones are usually sold for aquariums and bettas specifically. For example, we have a number of decorative stones on our website.

  213. avatar

    Hey im designing a self sustaining aqaurium using an old wheelbaroow and I coated it in a paint that’s used to prevent metal from rusting cause the wheelbarrow im using is really old.Was just wondering if its safe or if i should add on a layer of plastic.

  214. avatar

    Hello Kim, I see that you’ve asked a similar question on two of our blogs so I’ll add this reply to both. As we discussed in both blogs, metal is not safe and nothing will make an unsafe material 100% safe for fish. You can try using a pond liner or coating the wheelbarrow in a fish-safe material like the FlexSeal Liquid discussed in a previous comment but keep in mind that any moisture that reaches the metal can cause it to leach into the water. Rusted metal will also because structurally unsafe over time and can collapse or become too weak to hold water.

  215. avatar

    Hello Rachel, As we discussed in this blog, glass is safe as long as the glass itself is colored and not painted or glazed with the color. It looks like the link you posted says that the figurine is made using colored glass and is not painted so it should be safe for your aquarium.

  216. avatar

    Hi there! So helpful!

    How would PlayMobil or Imaginext toys do in a freshwater tank.

    Thank you for your help!!!!

  217. avatar

    Hello Homer, Plastic toys are usually safe as long as they don’t have any metal parts (be sure to check the joints for figurines) and as long as the plastic itself is colored and the pieces don’t have stickers or decals. If you scroll up through these comments, you’ll see another reply to a very similar question with a photo of a toy action figure used in one of our tanks here with some other suggestions.

  218. avatar

    Hello Eileen:

    I just purchased a beautiful decoration for my aquarium made with resin, but I’m concerned because it has blue writing on it, which I’m assuming has been painted on. I have some clear Acrylic paint here (Kryon) that was used for something else. Is the acrylic spray paint safe to spray on this ornament and put in the tank? Or should I use enamel? I used enamel on a few more decorations that weren’t made for aquariums, but after a few months of washing the ornaments during tank cleaning, the enamel started coming off. I didn’t see any floating in the tank, but it was peeling off when I was cleaning the ornaments. So can I use acrylic instead? I’m assuming acrylic is safe for aquariums, since my tank is an acrylic tank and the fish are fine.

  219. avatar

    Hi Dee, We discuss some different types of paint in the third part of this blog series, More Decoration DIY: Material and Aquarium Suitability. Acrylic is not generally safe for underwater use. Some aquarists have had success with it but it is a water-soluble paint when uncured and doesn’t tend to hold up well when constantly submerged. Enamel is a safer option but it depends on the material it is being used on. I had issues in the past when using clear enamel nail polish on a rubber hockey puck, for example, because the enamel couldn’t adhere to the rubber properly. If the ornament you are using is an aquarium ornament, it should be fine without being coated; most aquarium ornaments are made from polyresin.

  220. avatar

    Hello Eileen:

    Thank you for your reply. The decoration isn’t for an aquarium, it is made of resin however as were the other decorations that I painted with enamel. I will purchase some clear enamel spray paint then, and let it cure for several days. Unfortunately I had already sprayed them with the acrylic clear spray paint, right before you answered my question. EEEEK. Is it okay to spray them again with the enamel paint over top of the acrylic paint now?

  221. avatar

    Hi Dee, I would recommend checking with the manufacturer of the paint you used to see if it is safe for underwater use, or if it is dishwasher-safe or safe for food items. If it isn’t, I wouldn’t recommend it for your aquarium as a general rule. Coating an unsafe material with a safe one isn’t going to guarantee that it will be safe for the aquarium longterm.

  222. avatar

    I used Krylon clear acrylic paint. I chek with them to see if it’s okay. Thanks Eileen!!

  223. avatar

    Krylon Crystal Clear Acrylic Coating Aerosol Spray is smudge-proof and moisture-resistant. Use it to provide a barrier between your art work and the elements.

    The manufacturer says it’s more of a sealant and can be used for indoors and outdoors.

  224. avatar

    Hi Dee, Judging by the answers Krylon provided to other customers on the Q&A section of their website for this product (http://www.krylon.com/products/crystal-clear-acrylic/), I wouldn’t use that in an aquarium. Their answers regarding using the product outdoors and on the foodsafe questions, I wouldn’t trust it in an aquarium.

  225. avatar

    Oh wow!!!This is disheartening, as one of those decoration items was expensive. Bummed!!

  226. avatar

    Hi there, thanks for all the great tips shared on this site!

    My son is a Godzilla freak and I thought it would be cool to add his favourite character to our freshwater tank. Would a vinyl bust bank be safe for aquarium use, or would it need to be sealed?


    Many thanks!

  227. avatar

    Hi Stevie, I don’t see anything on the product descriptions that stick out as being unsuitable. You could try contacting the manufacturer (http://www.diamondselecttoys.com/) and asking them about the durability to be sure (try asking if it is dishwasher safe, which usually means it would be safe for your aquarium), but it is probably safe without sealing. Just keep a close eye on it over time to make sure the paint isn’t breaking down. To avoid any fish getting stuck in the bank, you can seal the openings close or fill it with sand or gravel.

  228. avatar

    Hi Eileen,

    Many thanks for your advice. I’ll be sure to check back in and let you know how I get on!

    Thanks again

  229. avatar

    Hello! I am trying to personalize our fish tank and have heard that sculptey modeling clay is safe once baked in the over and that acrylic paint (such as folkart acrylic craft paint) is safe to use to paint the decorations with. We have some small goldfish but we want them happy, healthy and entertained. Is this a safe way for me to add to their environment. I’ve already looked on line extensively and no one sells the pieces we are wanting in our tank.

  230. avatar

    Hi Jen,
    You can read more about different types of materials and their suitability for aquariums in the third part of this series, “More Decoration DIY: Materials and Aquarium Suitability“. Acrylic paint is water-soluble and I wouldn’t recommend using it in an aquarium. Some hobbyists have used it but it is more of a risk. Enamel paints are a safer and more durable choice; they can usually be found in model-making sections of art or craft stores, or nail polish can even be suitable once cured.
    Sculpey is a bit of a grey area. Some hobbyists have used it and been happy with it but it really depends on the type of Sculpey clay you choose. I’ve checked with the Sculpey company in the past. From a previous comment reply in May 2015:

    “I checked on Sculpey’s website and their FAQs page says “While our clays are non-toxic, we have not done any testing on any of the products to be used in aquariums.” Polymer clays are almost like plastic and it looks like a lot of people have used them successfully in snowglobes but it doesn’t look like many have tried using them in aquariums. I would think they’d probably be safe as long as they are fully cured and fired but you’d want to monitor their condition in the tank. The material itself is non-toxic but the durability may be questionable. The Sculpey FAQs page also has a list of their clays by durability; I would definitely go with the most durable clays over the least durable ones to be safe.”

  231. avatar

    Thank you so much for your help!

  232. avatar

    can i have open pcv pipes under the sand bed?

  233. avatar

    Hello Jose, PVC pipes are generally safe for aquariums; we use them in our store tanks a lot. I’m not sure what you are referring to by open and under your sand bed but you would not want to use them in such a way that it creates dead spots or anoxic conditions as this would be very harmful to the tank.

  234. avatar

    Hello Eileen. I just bought an aquarium and would love your advice….instead of using the boring plant background posters at the back of the tank; can I use mosaic? As far as I know there are some mosaic types that can be used in water. I’m just unsure on the impact it would have on my fish.

    Thanks in advance for your time!

  235. avatar

    Hello Lise, It would depend on the kind of tank you have (freshwater or saltwater), the water parameters (temperature, pH, hardness), the types of fish and the materials that the mosaic tiles, grout and adhesive is made out of. I would recommend reading through all three parts of this series – particularly the entry “More Decoration DIY: Materials and Aquarium Suitability” – for more ideas on what to specifically look for when choosing something for your tank. If you have a type of mosaic in mind, you can always contact the manufacturer for more information on if it is safe for use in ponds or if it is food-safe or dishwasher-safe for durability.

  236. avatar

    Hi there,
    I was wondering if you could help me ? we have just got a 190 litre tank and would like to put in a stone statue of a Buddha that has just been purchased for the tank from a garden centre. It has been soaked and scrubbed but I am worried it may not be safe. any advice would be much appreciated.

    Thank you


  237. avatar

    Hello Kacey, The material used for the statue would be a major factor in determining if it is safe for your tank, as would the type of tank and fish in it.

  238. avatar

    Are precious moments safe to put in a fish tank?

  239. avatar

    Hello Donna, That may be a better question to contact the Precious Moments company directly for an answer but based on the information I’m seeing, it doesn’t appear so. In the Cleaning Instructions I found on their website, it looks like they must be completely dried before displaying and that abrasives would harm the paint, leading me to believe that the conditions of an aquarium would probably harm their structure and finish. Several items I saw on their website also say “Hand Wash Only”; as we discussed in this blog, the Dishwasher Rule is a good safety baseline. If it isn’t dishwasher safe, it probably isn’t aquarium safe.

  240. avatar

    Hi my question is can you use bathroom backsplash decoration inside of an aquarium?

  241. avatar

    Hi George, It would depend on the type of backsplash you are using. Most tile should be safe but it depends on what it is made out of, the type of decoration on it, if it was coated with anything like a mildew preventative, etc..

  242. avatar

    Hi, I’ve always kept land hermit crabs but have recently switched to freshwater fish. I know not to use the tanks from the hermies for fish (because the hermies peal off all the seals around the edges) but I wasn’t sure if there was any reason a fish couldn’t use the decor after the hermies. Any ideas?

  243. avatar

    Hello Kylie, That would depend on what type of decor you are referring to. Decor made of natural materials like wood or fibers may decompose if underwater constantly and some materials can change the water conditions. You would need to check each material separately to make sure it is safe.

  244. avatar

    I want to repaint my aquarium decor but not sure what’s safe to use. I have a treasure box and two ships that I retouched the paint with matte finish acrylic paint and I purchased Krylon Clear Polyurethane to seal it. Is the Krylon Clear coat safe to use in my aquarium?


  245. avatar

    Hello Taneka, Acrylic paint is water-based and is not a safe choice for an aquarium regardless of what is used to coat it. As we discussed in all three parts of this blog series, clear-coating an unsafe material doesn’t make it completely safe. Any moisture that gets through or beneath any clearcoat you use will affect the piece. Enamel paints and clearcoats are a much safer option if you are painting your own pieces. For more recommendations on paints and safe materials, be sure to read through all three parts of the series…the links are above at the bottom of this blog article.

  246. avatar

    Hello I am currently trying to decorate some fish tanks with bettas and I was wondering if using imitation pearls and wedding table decorations (little diamond shaped plastic) would be safe for my fish? Thank you!

  247. avatar

    Hi Jacqueline, The pearls probably wouldn’t be safe. Most craft-store pearls are plastic with a opalescent coating that flakes off over time. The gems would depend on if they have a similar coating as well…clear glass or plastic, pr plastic that is itself colored and not coated with a colored glaze, would likely be safe but again, avoid anything with a decorative coating that will flake off over time. Decorative aquarium gravels with a pearl or gem-like look are pretty common though, and we also sell large decorative glass rocks that have a pretty cool gem-like or ice-like look in a tank as well if you have the room for it.

  248. avatar


  249. avatar

    I have some white coral [not live]. From my saltwater tank. Can i paint it with acrylic and use it in a freshwater tank.

  250. avatar

    Hello David, Coral skeletons wouldn’t be an appropriate choice for a freshwater tank. In the lower pH of most freshwater tanks, they would begin to dissolve and affect the water quality and the parameters that most freshwater fish need. Painting it wouldn’t make it safe. If you like the look of coral skeletons for your freshwater tank, I would recommend artificial ornaments instead.

  251. avatar

    Hello, I have a 55 gallon freshwater tank. I was wondering if I could use aquarium silicone sealant to brush on a 10 inch action figure and some accessories to make safe for my fish. Thank you.

  252. avatar

    Hi Twana, Aquarium silicone would be too thick to coat anything in. Clear enamel model paints, spray paints or even nail polish can be used to coat a decoration but as we discussed here, if something isn’t safe for your tank to begin with, a clearcoat isn’t going to make it 100% safe. Any moisture underneath the clearcoat or that can get in through a crack will affect the decoration and can damage it or cause it to leach materials into the water. I would avoid using anything delicate, organic like wood, or metal of any kind. If you can find plastic, ceramic or polyresin pieces without organics or metal, those would probably be safe, depending on the water conditions in your tank.

  253. avatar

    I have fireking teacups that have a gold colored metallic paint around the rim.


    Do you think that’s safe to use in an aquairum?

  254. avatar

    Hi AG, The link you provided doesn’t seem to be valid but from what I was able to find on Fire King tea cups, it looks like they are a mid-20th Century vintage brand? The colored glass pieces would probably be safe but I wouldn’t trust painted or decal pieces since they probably weren’t made with modern durability or materials. You could try running one through a few dishwasher cycles to see how it holds up but given that they are vintage and collectible, I wouldn’t risk them in an aquarium myself.

  255. avatar

    Trying to make a fish tank for my girlfriends job she works in a police station and would like to have a police car in the bottom of the tank is this doable?

  256. avatar

    Hi Samantha, It is absolutely doable! The key is finding a suitable police car. Look for something without metal parts and without decals or stickers that can soften and degrade underwater. Try the toy section for plastics like Legos or model-building kits that you can leave the decals off of. If an otherwise safe piece has just a small decal, a few coats of clear enamel nail polish will help protect it but won’t make it completely invulnerable. Avoid metal entirely (check the wheels if you get a model, for example, and make sure there are no metal axils). Anything dishwasher-safe is usually tank-safe as well, if her station has mugs or glassware or something similar.

  257. avatar

    Hi everyone! I’m pretty new to 3d printing and I have many questions on the subject, so I hope you won’t get mad at me for asking here at least a few of them. I think before I’ll get seriously into sculpting I should focus on the software itself, and that’s what I’d like to ask you about. Mainly, should I look for the most simple CAD I can find or would it be better to look for something more complicated? I’m worried that I’ll get some undesirable habits while working on simpler software. Right now I am using some online software called SelfCAD (I didn’t have to download anything). I’ve read some good opinions about it, but maybe you could share yours as well? The second question is about the software as well: should I search for CAD software that will allow me design and slice it in it, or should I use a different software for each of them? The one I’m suing allows me to do both i it. Will it even make a difference? Weirdly, I couldn’t find the answer to that, as it seems like most sites want to focus on the very basics (like what is 3d printing and so on), and while the answers to those questions are fine, it seems like no one wants to go into the details (it looks like some of them even steal from each other! I swear I’ve read the same answers to the same questions on at least 3 different articles) but I’m getting off-topic… The last question is about 3d pens. Would it be possible to somehow convert whatever I draw with a 3d pen to a 3d model in a software? For example, if I’ll draw a cat with 3d pen, would it be possible to get its outline in a software? I’m not sure how that could even work, but the very idea sounds appealing to me. Anyway, I think I’ll stop here just in case no one will answer me and all of this writing will go to waste. I’m sorry that I’m using your content to ask questions, but I hope you’ll understand and help a rookie like me. Anyway, thank you for posting. I learned something from this and that’s always appreciated. Thank you, and I hope to hear back from you very soon 🙂

  258. avatar

    Hello Frances, I’m afraid we wouldn’t have any information on that here on our aquarium and fish blog. I would recommend asking your questions on a blog or site about 3D printing and software.

  259. avatar

    Hello I purchased a mini replica thin tin metal diving helmet for my fish tank. Is this okay to place inside?

  260. avatar

    Hello Brandon, Tin would not be safe to put in an aquarium. I would expect that to rust pretty quickly.

  261. avatar

    Will putting chandelier hanging pieces harm my fish while in the tank for decorating?

  262. avatar

    Hi Kim, I’m not sure what you mean by “Chandelier hanging pieces”. If the materials are safe, they should be fine. If they have an unsafe material like metal, unsafe paints or glazes, organic material or another unsuitable material like those we’ve discussed in these blogs, I would leave it out. I would recommend reading through all three parts of this blog series to see if that helps you determine if the pieces you are looking at are safe, or if you would like to go into more detail about the “chandelier hanging pieces” you are referring to, I can try to help you figure out if they are safe.

  263. avatar

    I’m thinking about cutting an extra hole is hollow store bought aquarium safe fake aquarium rock. Will this affect my tank adversely?

  264. avatar

    Hi Paul, If it is already an aquarium ornament, it is likely safe but it would depend on what the rock is made out of. Most aquarium ornaments are poly-resin which would be fine for your tank.

  265. avatar

    Hey, super interesting thread! I was wondering is it tricky to notice if something is painted or is dangerous for a tank? I was wanting to decorating my tank for the seasons, specifically Halloween, I was thinking of picking up a Halloween figurine at a craft store, is that generally safe?

  266. avatar

    Hi Mechlin, Glad you are enjoying it! It can be tricky to identify if something is safe, particularly if you aren’t sure what it is made out of or covered in. Generally speaking, polyresin and unglazed glass decorations are safe (if the glass is colored, make sure the glass itself is colored and doesn’t have a colored glaze on top of it), anything safe for food use is aquarium safe (plates, mugs, bowls, etc), and anything dishwasher safe is aquarium safe. Colored plastic figures like Legos (without decals) are usually safe as well. I’ve used craft store decorations in tank in the past that seemed safe but the paint would start to soften up and scratch off easily after being in the tank for a little while. If you are able to identify a manufacturer on whatever piece you are looking at and can contact them directly, I would recommend asking them about the materials they use. The good news about Halloweek decorations particularly is that there are lots of skeletons and “scary”-themed aquarium decor on the market already so you may be able to find something to match your theme that is already for aquariums.

  267. avatar

    Hi. I’m trying to do a starwars theme in my new tank and there isn’t much available in the tank decor market for that. So I was wondering is it possible to buy basic plastic figures and use them in the tank or should I seal them before.

  268. avatar

    Hi Jess, I would recommend reading through all three parts of this series for guidelines on what types of figurines to use and how to tell if they are safe.

  269. avatar

    On repainting tank ornaments would you know if Testors paint is safe and should clear coat also be added. Are water based paints ever used, And can clear epoxy water base be used as sealant. Cliff

  270. avatar

    Hi Cliff, Testors appears to be a brand name with lots of different kinds of paint. As we discussed here, enamel paints are usually safe but water-based paints and many other kinds of paint are not safe to be used in water.

About Eileen Daub

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Marine Biologist/Aquatic Husbandry Manager I was one of those kids who said "I want to be a marine biologist when I grow up!"....except then I actually became one. After a brief time at the United States Coast Guard Academy, I graduated from Coastal Carolina University in Myrtle Beach, South Carolina in 2004. Since then, I've been a marine biologist at That Fish Place - That Pet Place, along with a Fish Room supervisor, copywriter, livestock inventory controller, livestock mail-order supervisor and other duties here and there. I also spent eight seasons as a professional actress with the Pennsylvania Renaissance Faire and in other local roles. If that isn't bad enough, I'm a proud Crazy Hockey Fan (go Flyers and go Hershey Bears!).