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Aquatic Science Fair Projects for Aquarium Lovers

With the new school year getting underway, it’ll only be a matter of time before the first science fairs and lab experiments start up. We get lots of students visiting or contacting us in search of ideas and test subjects for project ranging from the simple to the complex so I thought I’d share some tips and some of our favorite ideas for easy (and affordable) aquatic science fair projects for students of all levels.

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Before you begin…

Before you start any experiment or project involving live plants or animals, it is important to make sure you are prepared for the maintenance, care and cost of the experiment and livestock they are taking on. We’ve had many students that have a great idea for a project involving crabs, jellyfish, “Nemo” clownfish or other animals but don’t realize how much work and supplies are going to be needed to keep these animals healthy. They are also a commitment after the experiment is done; fish aren’t disposable and you have to be ready for them to go from Test Subject to Pet at the end of the project. Some experiments also require multiple subject that each need their own setup and supplies.

 

Time is another important factor to consider with these projects. Many experiments involving fish and plants are going to take some time before you will really start to see results like growth or changes to color or behavior. It can take at least a few weeks to reach any conclusions so if this is a last-minute project, you might be better off heading in another direction.

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What do you want to know?

The hypothesis of an experiment is the question you are trying to answer or what you are trying to prove or study. Depending on your grade level, this might be observing an environment or behavior or it might be testing a number of variables against a control. If one of the ideas here intrigues you but you aren’t sure where to go with it, ask your teacher or let us know and we might be able to help point you in a direction.

 

The project ideas here are mainly freshwater. Saltwater science fair projects are definitely possible, but they are going to be more difficult and expensive. Saltwater aquariums have a lot more factors than freshwater and need more equipment and maintenance to keep them healthy. If you already have a saltwater aquarium, you may be able to adapt one of these ideas to it or come up with your own but it may be easier to stick with a freshwater experiment if you don’t already have some saltwater experience.

Some Aquatic Science Project Ideas

Bettas and Aquatic Science Fair Projects

A male Veiltail Betta

The Betta (“Siamese Fighting Fish”) as a test subject

  • Betta splendens, also known as the Siamese Fighting Fish, is a good fish to use in aquatic studies and projects. They don’t need a lot of equipment or space, are easy to care for and are fairly inexpensive. They can be found in a lot of different colors and varieties but the most common kind that you will find in most stores is the Veiltail Betta. Some project ideas would be keeping bettas in a few different environments like a brightly lit versus darkened room, under a colored light like blue (“actinic”) light versus a white light, or warmer versus cooler temperatures. How do those changes affect each fish’s growth or coloration? You can take a picture every few days to compare any changes in their color or fins. Does the type of food or the color of the ornaments and backgrounds compared to the fish’s own color make any difference? Try different types or brands of food (flakes, pellets, frozen food, live food, freeze-dried food) to see how each affects the fish’s health.
  • A good way to measure growth is to weigh a specific amount of water in a container without the fish, then weigh the same container with the fish. The difference between the two weights will tell you about how much the fish itself weighs and changes in that weight will tell you if the fish has gained or lost weight.

 

Fish Food Nutritional Comparison

Aquatic Science Fair Projects and Fish Food Nutrition

Color-enhancing flake food like this is a common aquarium food.

 

  • Anyone who has gone shopping for food for their aquarium knows how many choices there are for your fish. Flakes, pellets, frozen, freeze-dried, live, color-enhancing, vitamin-enhanced…the choices can be overwhelming. At the time that I write this, we have over 400 different fish food items on our website alone! For a science fair project, you can compare several of these foods and see how your fish react; feed the same kind of fish in separate but identical environments the same amount of different types or brands of food at the same time of day and measure how this impacts their growth, health and behavior. Maybe one kind of food is advertised as color-enhancing or another has a different primary ingredient…does one kind give the fish brighter colors or make them grow more during the time frame of the experiment? The fish should all be in separate aquariums to make sure they are only eating “their” food but you can otherwise use any fish – goldfish, bettas, livebearers like mollies or guppies. You can use the same method as above to record their growth.

 

 

The Nitrogen Cycle and Aquatic Science Fair Projects

The Nitrogen Cycle

The Nitrogen Cycle and “Cycling” a New Aquarium

  • The Nitrogen Cycle is a process that every aquarium and contained body of water will go through as the helpful bacteria populations that take care of fish waste will go through. Every aquarist has seen this happen whether they realize it or not. As the first living critters in a tank produce waste or leftover food or other material decomposes in the tank, a bacteria known as Nitrosomonas change that waste from ammonia (NH3) to nitrite (NO2). Another population known as Nitrobacter will change that Nitrite into Nitrate (NO3), the end product of the cycle which is usually removed by water changes or plants that use it to grow like fertilizer. If the levels of Ammonia, Nitrite and Nitrate could be put on a graph throughout the process, they should look like three hills with their peaks coming one after another. Can you set up and “cycle” a new aquarium and use test kits to record these values at a specific interval (every 5 hours, for example) and see if you can recreate this cycle? Does the number of fish change the levels or speed throughout this cycle? What about if the tank is cycled with a dead “waste” like leftover food instead of live fish?
  • A project like this does use chemical test kits. The kits available from pet stores for aquariums are easy to use, but adult supervision should always be used around chemicals like these.

 

 

Fish Tricks

  • Did you know fish can learn? Fish like goldfish have been “trained” to recognize objects and do all sorts of tricks like swimming through hoops or under limbo bars. There have even been “soccer matches” between saltwater fish to celebrate the World Cup. Training fish, like most animals, is all about positive reinforcement. Some companies have even made training kits just for teaching fish. Some experiments have trained fish to recognize certain colors by putting food in cups of one color (like red) but not others (like blue and yellow). Once the fish begins to associate the red cup with food, does putting a red ornament in the tank or red background on part of the tank make them choose that over the blue or yellow? How long does it take, and does any kind of fish learn faster than others? You can try putting one fish through its paces or train a few fish to compare their learning styles.
  • Check out this video from Rochester Institute of Technology’s Professor Caroline DeLong to see how she taught a goldfish to recognize shapes

 

Hatching Brine Shrimp and Aquatic Science Fair Project Ideas

Brine Shrimp Hatchery Kit

Hatching Brine Shrimp

  • Brine Shrimp are popular as fish food in aquariums as well as in the wild, and there was a time that “Sea Monkeys” were popular as “pets”. Hatching brine shrimp can be an interesting endeavor. They can be easy to grow but need just the right salinity (salt level) and the newly-hatched shrimp will need equally tiny food. The baby brine shrimp also show a behavior known as “phototaxis”, meaning they are attracted to light. Brine shrimp eggs are inexpensive and can be purchased in their dry “cyst” form where they will hatch once back in the right water. Experiment with salt levels, food like phytoplankton and with light and see what factors make for the best hatches. Once the shrimp are hatched, they can grow to almost a half inch in length and make great fish food!

 

 

This is just a sampling of some concepts that aquarists face every day and there are a lot more out there like overfeeding, breeding and genetics in fish like guppies or mollies, water changes and water chemistry…the possibilities are endless! Popular aquarium fish are even ending up in important medical research. Have we given you any ideas for your next science fair project or laboratory experiment? What would you like to learn more about, and what are some of your favorite projects? Share your results and experiences with us…we’d love to see the results of your studies!

Aquarium Clean-Up Crew: How Many Snails Do You Need?

Hiring staff for any job can be tricky. You need to make sure you have the right number of qualified employees to handle the job, not just a lot of employees on your payroll that eat into your bottom line or ignore the job you’ve given them. Choosing a clean-up crew for your saltwater aquarium is similar; you need to make sure you have the right snails and crabs and other cleaners for the tank without too many that can deplete your resources or just not even do the “right” work at all. “How many snails do I need?” is only part of the question; making sure you are getting the ones best suited to the job is just as important.

 

 

The White-speckled Hermit Crab. Cute, but NOT an algae eater!

The White-speckled Hermit Crab. Cute, but NOT an algae eater!

Job Description and Qualifications

 

Hiring an employee without knowing their qualifications or describing the job doesn’t make much sense, whether it is renovations on your home or clean-up within your aquarium. Not all snails eat algae. Not all snails that eat algae eat the same kind of algae. Not all “algae” is even algae at all. And snails may not even be the best (or only) cleaners for the job; “detritivores” that eat the leftover food and waste (“detritus”) are also necessary for keeping a tank clean and healthy. The first step to choosing a clean-up crew is to identify what the problem is that you’d like them to help you solve. Algae is normal in any aquarium and having a basic clean-up and scavenger crew is a good idea but beyond that, if you have a specific problem like a cyanobacteria bloom, hair algae, green water or other issues, you may need a solution beyond a few snails. You may be seeing a symptom of a larger problem like poor water flow or lighting quality and unless that problem is addressed, it will keep coming back no matter how many snails or other clean-up crews you throw at it.

 

What are the working conditions?

 

It takes a different kind of person to paint the walls of a house than it does to paint the cables at the top of the Golden Gate Bridge. It also takes a different kind of critter to clean up a nano-reef than it does a rock-filled bare-bottom aquarium or a deep sand bed. Some hermit crabs can have difficulty reaching into small crevices and some snails can’t flip themselves over if they tumble off of the glass or rockwork. Some snails, starfish and other animals popular in aquariums also eat other snails or invertebrates and corals. Are the animals you are choosing suitable for the environment you have?

 

It’s all in the job security

Some of the most popular saltwater clean-up crew snails

Some of the most popular saltwater clean-up crew snails

Contrary to popular belief, snails and hermit crabs are not disposable or short-lived or robotic lawnmowers that feed on nothing but salt and sunlight. If they have plenty of food and proper care, they can live for a long time. If they run out of the right food, they won’t survive so overloading a tank with cleaners to keep it spotless is only going to end up with losses. When snails and other cleaners die and decompose, they affect water quality. When water quality goes down, algae will bloom. When algae blooms, you’ll need to add more cleaners. Starting to see where this cycle goes wrong? Avoid the urge to overload on a massive cleanup crew and start with a basic foundation. Once you can observe where they need the help, supplement with some helpers for that purpose (like aerating the substrate, cleaning the glass, targeting hair algae or other trouble areas).

 

The magic number is…

 

Just like the old “inch-per-gallon” rule that is still floating around for fish, there are some stocking guidelines for clean-up crews. Some of the most common include a snail per gallon or a hermit crab per five gallons but again, this only works if that snail or hermit crab is suitable. To help you out in making some selections, we have basic Algae Packs with recommended tank sizes. You can start with the one closest to your tank size and give it some time. You can always supplement later or get a specialty algae pack to target a specific need like detritus or hair and buble algae. Remember, hiring is always an ongoing process!

 

You're hired!

You’re hired!

 

Algae Eaters and Plecos for Small Freshwater Aquariums

Finding the perfect new addition to an aquarium is often like finding the Holy Grail to many aquarists. We all want the perfect little helper to keep the tank clean so there’s less work for us to do (and so our tank is cleaner and healthier, of course) but many “algae eaters” get too large for smaller aquariums and many others like the group of fish known as “plecos” don’t even eat algae at all. So what are the best plecos and algae eaters for small freshwater aquariums? Here are a few of our favorites that are some of the best choices for smaller community aquariums:

 

Bushynose & Bristlenose Plecos (genus Ancistrus)

Starlight Bristlenose Pleco (Ancistrus dolichopterus L183)

Starlight Bristlenose Pleco (Ancistrus dolichopterus L183)

  • PROS: Lots of variety in color and pattern, small size, vegetation-heavy diet (including algae), community-friendly.
  • CONS: Some species grow larger than others, needs meaty foods as well, underfed fish may eat live plants.
  • BEST SUITED AS: A community algae-eater and bottom-feeder.

 

Plecos from the genus Ancistrus usually have “Bristlenose” or “Bushynose” somewhere in their common names, a nickname that comes from the whisker-like frills that develop on most adults. They are usually more prominent in adult males but some females may get them too in some species. Different species in this group have different requirements, but they are generally among the smallest plecos. While they eat some meatier foods as well, most appear to eat mostly vegetation.

 

 

Clown Pleco (Panaque maccus L104)

Clown Pleco (Panaque maccus L104)

Clown Pleco (Panaque maccus L104)

  • PROS: Small size, easy-going temperament, fairly wide-spread diet.
  • CONS: Need driftwood for grazing, not primarily an algae-eater.
  • BEST SUITED AS: A general clean-up bottom-feeder for community aquariums.

The Clown Pleco is a popular small pleco. As with other Panaque plecos, these fish are omnivores and feed about equally on plants matter and meatier foods. Panaque plecos are also unique in that they actually feed on driftwood as well; make sure you have driftwood décor in your tank for these fish to graze on.

 

 

 

Hillstream Loaches

Reticulated Hillstream Sucker (Sewellia lineolata)

Reticulated Hillstream Sucker (Sewellia lineolata)

  • PROS: Eats algae, can be kept in groups, unique and unusual appearance.
  • CONS: Needs high flow and pristine water, vulnerable to aggressive tankmates and poor water chemistry.
  • BEST SUITED AS: A unique addition to a suitable community aquarium where it incidentally may help eat algae but isn’t the primary algae-eater.

Hillstream Loaches have flattened guitar-shaped bodies and are often mistaken for plecos. They cling to rocks in the fast-moving mountain stream where they come from much like plecos cling to surfaces. Hillstream Loaches need well-oxygenated and well-filtered tanks and don’t do well with nippy tankmates or in tank with less-than-pristine water quality. They do eat some algae however, as well as other detritus and leftover sinking foods.

 

 

Otocinclus Catfish

Dwarf Suckermouth Catfish (Otocinclus sp.)

Dwarf Suckermouth Catfish (Otocinclus sp.)

  • PROS: Small size, safe for planted tanks, primarily algae-eaters.
  • CONS: Can be sensitive to stress, can starve if they can’t find enough to eat.
  • BEST SUITED AS: Algae-eating housekeepers in planted community aquariums.

 

There are a few very similar species that are commonly grouped together as Otocinclus Catfish (“Oto Cats”) or “Dwarf Suckermouth Catfish”. Most are brownish-grey in color with a black stripe but some like the Zebra Oto (Otocinclus cocama) have a more ornate pattern. These fish stay under two inches in length and are great for eating algae off of plants without harming the plants. They can be a bit finicky and sensitive though so only keep in a stable, healthy aquarium. They are also best kept in groups so plan tankspace accordingly.

 

 

Rubbernose Plecos (Chaetostoma sp.)

Spotted Rubbernose Pleco (Chaetostoma sp.)

Spotted Rubbernose Pleco (Chaetostoma sp.)

  • PROS: Moderately small adult size, eats some algae, community temperament.
  • CONS: Not a primary algae-eater, can be bulky for very small tanks.
  • BEST SUITED AS: A general bottom-feeder for community tanks over about 30-45 gallons.

 

Like the Clown Pleco, Rubbernose Plecos are some of the most common smaller plecos available. They also have a very familiar pleco-like appearance that many novice aquarists associate with algae control. They are not exclusive algae-eaters however; this is another omnivore that needs about equal parts meaty food and plant matter. These fish are pretty middle-of-the-road overall: moderate adult sizes, eats diet for about half their diet, neutral coloration, moderate temperament.

 

 

Freshwater Nerite Snails

Freshwater Nerite Snails (Neritina sp.)

Freshwater Nerite Snails (Neritina sp.)

  • PROS: Colorful shells, safe for plants, small size.
  • CONS: Limited availability, may reproduce, may be vulnerable to predators.
  • BEST SUITED AS: Algae-eating grazers for small planted aquariums.

 

Nerite Snails are popular for saltwater aquariums but some species are found in freshwater as well. These snails are much smaller than some of the other less-suitable and more invasive freshwater snails like Apple Snails or Trapdoor Snails. They mainly eat smaller algaes like the ones that cause spots on glass but usually won’t harm plants. These snails also appear to bred less frequently in most aquariums than the more common Apple Snails. Make sure the ones you get are from freshwater; a saltwater Nerite will not survive being moved to a freshwater tank.

 

Freshwater Shrimp (Caridina sp.)

Several freshwater shrimp (Caridina sp.)

Several freshwater shrimp (Caridina sp.)

  • PROS: Safe for plants, small size, can be kept in groups.
  • CONS: Limited availability, vulnerable to predators, very small.
  • BEST SUITED AS: Algae-eaters for planted nano tanks with peaceful or no other tankmates.

Small freshwater shrimp like the popular Cherry Shrimp and Amano Shrimp can be ideal grazers, especially for nano tanks (under 1-2 gallons). Some are clear, some are colored or have colored markings and they can be kept in groups. However, most of these shrimp are very small; you may not see them often and can’t be kept with anything remotely predatory.      

 

 

 

As always, the best algae-eater for your tank depends on its tankmates, the size of the tank, the water parameters and other such factors but hopefully this helps give you some alternatives to fish that may be too big or otherwise unsuitable to your needs. If you need more help in making your best choice or have a favorite of your own, feel free to comment below!

Aquarium 101: Starting a Siphon for Water Changes and Acclimation

Starting a siphon to move water from one container to another is a basic function in aquarium-keeping. Among other random uses, we use it in water changes, emptying or filling an aquarium, acclimating new livestock, and making filters work correctly. Since it is something that we use so often – especially in a retail environment like That Fish Place, it can be one of those actions that we take for granted and just assume everyone knows how to do but everyone has to be taught before they know, right? So here are some tips and tricks to have you siphoning like a pro in no time.

 

siphon principle

Uploaded to Wikipedia Commons by user Tomia

How it works

Before we discuss how to do it, it helps to know what is happening. A siphon uses a vacuum inside of the tubing to move liquid in a way the same as using a straw to drink. When you use a straw, you suck on the end to remove the air from the tube. As the air is removed, there is a vacuum inside of the straw and the liquid in the cup moves up to fill the space. If there is a hole or crack in the straw or if your mouth isn’t completely sealed around the end of the straw, it won’t work.

Instead of moving the water up a straw, a siphon uses gravity to move water  from a container at a higher elevation down into a waiting lower-level bucket or other container. When a vacuum like the straw is created in the tubing, the water rushes in to fill it and gravity keeps it going into the lower container until both are even or the siphon is “broken” by allowing air to get into the tube (usually just by removing the higher end from the water). It is creating that vacuum that can be the tricky part for aquarists.

 

 

 

  • Method 1: By mouth
  • I’m going to get this one out of the way because it is the most common but also the least adviseable. Its easy, its quick, we’ve all done it…and most of us have ended up with a mouthful of aquarium water in the process at some point. This isn’t the safest method and is why every gas pump you use will have big “do not siphon by mouth” warnings on them. In this method, the higher end (End A for the rest of this blog and the left side of the graphic above) is put into the aquarium and the lower end (End B and the right side of the graphic) is held below the level of End A. You would then put your mouth over End B, suck on it like a straw under the water starts flowing and release it into the bucket before getting a mouthful of it. There is a risk of getting anything left in the tube in your mouth as well as anything in your aquarium water; DO NOT use this method if you have medicated or used any other chemicals in your aquarium!!

 

  • Method 2: SubmersionSubmersion
  • In this method, we start off with the air removed from the tube by completely submerging the tube in the aquarium first. Once all the air is out, plug both ends with your hand or a finger and remove End B from the water. Once End B is lower than End A and over your second container, let go of both ends. The tube would then empty into the bucket and start the siphon from the aquarium. Alternatively, you can also fill the tube with water first if you can’t fit it safely into the aquarium to submerge it; just hold the ends closed until you have them in place. This method tends to work better with slightly larger tubing (0.5” diameter or more) rather than thin airline tubing like those used for acclimation.

 

 

  • Method 3: Power-startingPower starting
  • Instead of drawing the air out through End B, this method forces it out from End A. If you have a powerhead or pump in the aquarium or a powerful output into the tank, you can use that to start the siphon. Hold End A up to this source and seal it as tightly as possibly with your hand until the water is coming out of the other end of the tubing. When you remove End A then (and get it in the water immediately without allowing any air in, if it is above the surface), you should have a good siphon going. Again, this tends to be more effective with larger-diameter tubing than the thin stuff. Some companies also make gravel vacuums that fasten directly to a faucet and use a similar method of starting the siphon “automatically”.

 

  • Method 4: Siphon “Starters”

Syringe

  • Some gravel vacuums have starter bulbs built into them for this but if yours doesn’t, you can create your own. The built-in starter bulbs would act like your mouth and lungs in Method 1 by sucking the air out of the tube to start the siphon. For thin-diameter tubing like the airline tubing used for acclimation, you can use a syringe plunger like the ones that come with most test kits as a starter. With End A in the aquarium, put the tip of the depressed plunger into End B, then draw out the stopper. This sucks the air out of the tube and starts the siphon for you. While this one isn’t as effective for the bigger diameter tubing, you can try larger syringes,  turkey basters, or irrigation bulbs from the health and first aid aisle at the drug store for this purpose.

 

The Breaking Point

To end your siphon, just take End A out of the water, raise End B higher than End A or allow air to get into the tube and it will be “broken”. Alternatively, if your siphon stops, check to see if any of those things have happened or if something is clogging up your tube. If you do notice that your gravel vacuum keeps getting clogged where the wider vacuum attaches to the more narrow tubing, just tilt it a bit more or tap it lightly and the heavier gravel should fall. If you are using your siphon to acclimate your new livestock, you can tie a loose knot in the end of the tubing or add a small valve to help control the flow once you’ve gotten your siphon started. If you have any questions or problems starting your siphon, or if you have a method that I haven’t mentioned, let us know!

Aquarium Gravel and Substrate vs Bare-Bottom tanks: Pros and Cons

One of the first purchases most aquarists will make for a new aquarium, be it freshwater, saltwater, reef, discus, goldfish, cichlid or any other – is the gravel and substrate. It could be sand, crushed coral, Fluorite, neon pink pebbles, glass marbles or countless other materials  but it all tends to be the very first thing to go into an empty aquariums. But….why? Do you really need it? Are there alternatives? Much like the eternal home decorating debate of hardwood-versus-carpets, the battle brews among aquarists over what covers the bottom of their aquariums, a layer of substrate or nothing at all.

 

So why has substrate become such an integral part of the aquarium culture, and why are some aquarists now looking past it in favor of the bare glass or acrylic bottom of their aquariums? Much of it has to do with our understanding of the aquarium ecosystem now over what we knew years or even decades ago. Even as recently as five or ten years ago, undergravel filters were thought as indispensable for all types of aquariums and as such, gravel was thought vital to their function. We’ve come a long way with filtration technology since then, and we’ve also come a long way with understanding how the water chemistry in our aquariums functions. Alternatives and advancements have made the old undergravel systems nearly obsolete and the aquarium gravel that went on top of them is become more of an Option instead of a Requirement.

 

That said, how do you make the choice? Like so many other parts of our hobby, it comes down to personal preference and your goals. Bare-bottom tanks are becoming more common and have their benefits of substrated tank and vice versa; substrate is still a better choice than going bare for some other types of tanks. Weigh your options carefully before you choose which one is right for you. We’ll go over a head-to-head comparison in the major factors to consider to help you make your decision.

Cleaning a Fish Tank

 

The ever-iconic Gravel Vacuum

The ever-iconic Gravel Vacuum

An aquarium that is easy to clean and easy to care for is the dream of most aquarists. Bare-bottom tanks win this category easily. Ever wrestle with starting the siphon on a gravel vacuum, then have it clog up repeatedly with gravel when you are cleaning? With a bare-bottom tank, a gravel vacuum isn’t needed; you can just use tubing to vacuum up any waste sitting on the bottom of the tank and water pumps or powerheads can be used to circulate the water underneath and behind the rockwork more efficiently. It can be a lot easier to scrub algae off of the glass bottom and sides without having to worry about missing some at the gravel line or getting bits of sand stuck in your scrubber as well. For tanks like reef aquariums with lots of rockwork, debris and detritus can get stuck under the rocks or in the back where your vacuum cant reach as well, causing the nitrate levels and algae blooms to increase. While not as vital in, say, a freshwater community tank, nitrate and algae can spell Doom (and Headaches) in a reef tank.

 

Aesthetics & Natural Environments

 

IMG_4312

A natural planted freshwater nano-tank

I have to give this one to Substrate. Surprisingly, flat panes of glass or acrylics just aren’t found at the bottom of most environments in the wild. Natural environments have sand, or mud, or pebbles or some other natural material. Besides just plain looking more natural, some animals also need this substrate to live normal lives. Some fish and snails bury themselves in it or find their food in it. Timid animals need it to hide or camoflauge themselves and in some specialized ecosystems, the substrate plays a vital role in the water chemistry. Most live aquarium plants won’t survive without a substrate to root into. Having a substrate also provides many more options in changing the look of the aquarium, whether its a natural substrate or a decorative one.

 

Aquarium Water Chemistry

 

This one is an even draw; both having substrate or having a bare-bottom can negatively and positively affect the water chemistry in an aquarium. Some substrates like crushed coral can buffer the pH and hardness of the water. For a saltwater tank with a target pH around 8.0-8.4, this is a good things. For a tropical tank with a target pH around 6.0-7.0, maybe not so much. A Flouorite substrate for planted freshwater tanks can give the plants some much-needed minerals and nutrients through their roots that a bare-bottomed tank can’t give them.

 

As much as this exchange helps, any waste that can get trapped in the substrate can hurt the tank. If waste becomes trapped, it will decompose and increase nitrate, phosphates, ammonia and other negative levels which can lead to fish illness and algae blooms. As we mentioned before, this waste is much easier to get rid of in a bare-bottomed tank.

 

Microinverts, hitckhikers and other “bonus” tankmates

 

IMG_2091

Our bare-bottomed 700 gallon store display tank

Unexpected new arrivals like bristleworms can be the ban of a saltwater aquarist’s existance, and tiny little nuisance snails or flatworms can harass a freshwater aquarists to tears. Most of these critters live or reproduce to some extent within the substrate and getting rid of the substrate to go bare-bottom will help get rid of them. Unfortunately, it will also get rid of the good critters like copepods and amphipods that can provide a natural food source to some of the pickiest fish and inverts. If you are making your choice to go bare-bottom to get rid of the nuisance critters, weigh the needs of the rest of your tank carefully to see if they can do without the good to get rid of the bad.

 

The (Bare-)Bottom Line

 

Choosing whether to add substrate to your aquarium or stick with the bare tank ultimately rests on you. Most aquariums will survive either way but one choice may be more successful than others. In our store, we have both bare-bottom tanks and tanks with substrate among our display tanks as well as the tanks we sell fish out of. Stocking these tanks is determined by the needs of the fish and the care that they need. Generally, coral-only reef tanks can go bare, planted freshwater tanks can’t; freshwater fish-only tanks might not need it but saltwater fish-only tanks (or fish-only with live rock) will do better with it. If you can’t decide which way will be more successful for you, we’d be happy to help you make the best decision for you and the success of your aquarium.