Home | Aquarium Equipment | Pure Confusion – Finding the “Right” Water for Your Aquarium

Pure Confusion – Finding the “Right” Water for Your Aquarium

Water SamplingOne common question that we receive about setting up new aquariums is about the most basic ingredient to the aquarium, the water that goes into it. There are a lot of terms that can get confusing when someone is trying to determine how to fill their aquarium and from what source. The options can be staggering – tap water, bottled water, prefilters, and so on – and starting with the right foundation can make all the difference, from the smallest betta bowl to the largest reef system.

Tap Water

This is probably the easiest and most accessible water source in most areas. Whether you get your water from a municipal water sources or from a well, it doesn’t get much easier than going to the nearest sink to fill your bucket or tank. Its ease is definitely a benefit, but keep in mind that municipal water sources will usually contain chlorine or chloramine to kill bacteria and well water sources may contain phosphates or other organics. Tap water can be used, but should be treated or purified to remove these materials before it goes into your aquarium.

Reverse Osmosis (RO) and De-ionized (DI) Water

RO/DI Units are very popular among aquarists. Although Reverse Osmosis and De-ionization are different processes, they are often done in conjunction and in combination filtration systems. In these units, water is forced through a membrane (RO) and through resins (DI) that remove minerals and compounds leaving the water very pure. A unit can be installed to filter tap water and make it safe to use for aquariums, but does not, in itself, remove chlorine and chloramine compounds used in tap water purification. Most newer RO/DI units have carbon prefilters to remove chlorine and chloramine before it gets to the aquarium. While RO/DI filtration removes most of what an aquarists does not want in their water source, it can also remove some of what one does want so RO/DI water must be buffered and “remineralized” before being used. Reef aquarists are the most common RO/DI users and since they use salt mixes before using the RO/DI water, they usually do not have to be concerned since the salt mix itself makes the water suitable for usage again. Anyone using RO/DI in a freshwater system would need to remineralize their water using a buffer appropriate to their system.

Distilled Water

Distilled water is one of the purest water types available. It is created by heating water and collecting the pure water that evaporates as steam while leaving solid impurities behind. This is not usually used by home aquarists since it tends to be expensive and more inefficient when it comes to tank maintenance, but distilled water is available in most grocery stores. Most often, it is questioned as a possible water source for smaller tanks like bettas, goldfish and community tanks and by new aquarists looking for an easier and “safer” solution.

Not necessarily. Since it is very pure and has had even more minerals and compounds removed than other processes, it is extremely soft and has no buffering capacity or mineral composition. As with RO/DI water, these minerals are often replaced if the distilled water is mixed with salt mixes for reef systems but it would need to be buffered before it can be used for freshwater or for a small system like a betta bowl. Without being buffered, the water chemistry parameters like pH can fluctuate wildly. For these smaller tanks and bowls, distilled water can be costly, inconvenient and even unsafe.

Spring Water and Bottled Water Sources

Spring water on MackinacBottled water is popular for those with small tank and for betta enthusiasts. Since it is available in most grocery stores and can be more convenient than dechlorinating tap water, many turn to bottled sources and different brands of spring water for quick water changes. While most spring water is filtered and safe to use, every brand is different and meets different standards. Most bottled water is filtered by reverse osmosis, deionization or distillation similar to the sources already discussed, and many brands add minerals back into the water to improve taste and nutritional value. “Spring water”, by definition, comes from an underground source and its mineral composition is affected by that source so its mineral make-up can vary as a result as well. It is a good idea to test a new brand for pH, hardness, phosphates, nitrates and other base readings before use, especially in a sensitive reef system.

Although the water sources may vary, the requirements of the fish, plants and animals we keep generally does not. If you have questions about how to make your water appropriate for what you want to put into it, feel free to let us know!



Spring water on Mackinac image referenced from wikipedia and originally posted by DaemonDivinus
Water sampling image referenced from wikipedia and originally posted by Alloquep


  1. avatar

    Hi, I am trying to farm Red Cherry Shrimp and the water in my areas PH and Hardness are extremely high. I have tried several PH neutral products and with multiple doses the best I can get is 7.6 using my API test kit. My first attempt at keeping these shrimp in my planted tank was a total loss. It is approximately a 20 Gallon tank with two pieces of small driftwood two air powered 20 gallon sponge filters and a small 20g CO2 system. any advice

  2. avatar

    Hi Christopher, High hardness is very difficult to fight against. I would recommend switching your water source rather than try to fight that water into submission. Since the tank is fairly small, you can purchase spring water for your water changes or invest in an RO (reverse Osmosis) unit for a more readily-available water supply. RO Units are pretty popular for situations like yours when a home water softener isn’t a practical solution and they can be found from aquariums stores like ours as well as home improvement stores like Lowes or Home Depot. You can read more about RO systems on our blog “So, You’ve Got Questions About Reverse Osmosis Water?

  3. avatar

    We have well water with an RO and water softening system. Should I use the straight well water, softened water or the RO & softened water to start my new freshwater tank for glo-fish? I’m confused as to which is best and if I still will need to treat the water with anything

  4. avatar

    Hello Dana, That would depend on the water parameters in your well water to start with. Not all well water is the same; the pH, hardness and even phosphate and nitrate levels in the water will vary depending on your area. I would recommend testing your well water right out of the tap to see what your starting hardness, pH and phosphate levels are to start with. GloFish will need a pH around 6.5-7.5 and soft to moderately soft water. If you use water from a water softener, you can generally use that straight into the tank. If you use water from an RO/DI unit, you will need to use a product like RO Right to add some minerals and buffering back into the water since the unit removes all of this.

  5. avatar

    Thank you so much for your reply! I bought a ph tester to check it out. You have been very helpful!

  6. avatar

    Glad to help, Dana. Enjoy your GloFish!

  7. avatar

    I have gouramis and my tank is smelly and brown can you help?

  8. avatar

    Hello Andrea, Aquarium water that is brown and smelly is usually a water quality issue but I would need more information to help you figure out what the best next step is for you. How big is the tank? How many gouramis are in it? How long has it been set up? How often do you do water changes? Have you tested the water quality and what are the result values for Ammonia, Nitrite, Nitrate, pH and temperature to start with? Do you have carbon in the filter, and if so, when was the last time you changed it? I would recommend getting that information together and giving our Fish Room staff a call at 717-299-5691 so we can help you address your tank more specifically.

  9. avatar

    I have a 3 gallon tank with a Betta. I am looking for a stable water source/solution. I have been using Spring Water and, as you noted above, I am seeing fluctuations in pH, hardness, and alkalinity.

    I am interested in using distilled water because I’d be starting with pure water. I would know exactly what was added to it. If I added a product such as Seachem Betta Basics or Seachem Liquid Neutral Regulator, would that solve the problem of pH fluctuations with distilled water? I also use Flourish liquid, Fluorish Excel liquid, and Fluorite–all of which would add micro and macro nutrients to the distilled water. Would this work? Or would I be better off sticking with tap water?

  10. avatar

    Hi Christina, A product like Kent Marine’s RO Right would be a better choice to remineralize distilled water. Both of the other products you mentioned will help buffer the pH but won’t raise the hardness which is necessary to stabilize it. They both also contain phosphate salts which can raise your phosphate (and algae) levels.

  11. avatar

    Great article; very informative and helpful!

    I am a beginner. I have a 40 gallon tank with four glo-fish and one platy. Chloramine is added to my city water. I can buy RO/DI water from my local pet store however it is a distance away from my home. So, would it be possible to use a water conditioner, such as Prime, to remove the chlorine and chloramine; would this make the water safe for the fish? Are these types of water conditioners effective at removing such chemicals from tap water? Thanks!

  12. avatar

    Hi April, Products like Prime will help condition against the chloramine. They don’t entirely remove it but they bind it into a less toxic form until the natural cycling of the tank can get rid of it. Be sure to check whatever conditioner you are choosing since not all of them will remove chloramine. They won’t remove any other chemicals from the water. Another one of our blogs, Treating The Treated – The Line Between Tap Water and Aquarium Water – goes into this topic in more detail.

  13. avatar

    Hi I have a small 5 gallon Betta tank and he does not seem to be doing well at all he is very inactive and just sits at the top and I’m wondering if it’s because of the water. I used tap water with tetra Betta safe conditioner and I’m wondering if I should use spring water, tap water or distilled water? Help I’m so confused lol!!

  14. avatar

    Hello Casey, Bettas aren’t extremely active to begin with and will spend a lot of time at the surface so there may be nothing wrong. They will also go through periods where they will be less active than other times. Testing the water to make sure it is safe for the betta (pH, Ammonia, Nitrite, Nitrate to start with) is always a good place to start and make sure that the water temperature is consistent and within a safe range since temperature can change more easily in a small tank. If your tank doesn’t have a filter, the water should also be changed at least weekly. The BettaSafe should make your tap water safe for the betta by neutralizing the chlorine and chloramines in it but spring water is also safe. I would avoid using distilled unless you buffer it before use like we discussed in this blog. Our Betta Species Profile and Care Guide may help you with some information on caring for your betta.

  15. avatar

    I have been flailing trying to cycle my tank (which is an aquasprouts setup for aquaponics)… I had tested water before fish and levels were all correct, so as a beginner, figured my tank was cycled, so I got fish (6 serpae tetras) which seem to be quite happy so far. Should mention that the local fish store suggested adding some nitrifying bacteria, which I did. my water started out marginally hard but now seems to be at the extreme hard level with pH remaining stable at 6.5. This morning I noticed the NO2 level has risen to 1. I initially used my Berkey water filter (which filters out chlorine and fluoride, but keeps minerals intact) to fill the tank and when hardness seemed to be a problem, I changed the water out 50/50 with snow. In a quandary as to what my next step is. RO water is only available at one shop locally, and a little on the expensive side, so think I will check out the spring water option. Comments?

  16. avatar

    Hello Gail, I would recommend reading through our blog “The Nitrogen Cycle and Conditioning Period in New Aquariums” and our article on The Nitrogen Cycle to help understand at least part of what is happening in your tank. A tank hasn’t even started cycling until fish or a nitrifying bacteria supplement are added and would usually take about 3-8 weeks after that, depending on the size of the tank and bioload. A spike in Ammonia, then Nitrite, then Nitrate is completely normal during this period.

    As for the hardness, what is the General Hardness (GH) or Carbonate Hardness (KH) in this tank and in your source water, what pH are you trying to reach or what are you looking to keep in the tank? Hardness makes it very difficult to change the pH and if it is coming from your source water, it will be difficult to alter. Water softeners and supplements may help or you can look into installing your own RO Unit in your home to produce your own much cheaper than purchasing it. Also, what kind of decor, substrate or rocks are in this tank? Certain kinds of rocks and minerals will raise pH or buffer hardness and if any of these are in your tank, you may need to replace them with something more inert.

    You can contact our Fish Room staff at 717-299-5691 or 888-842-8738 if you would like to discuss your tank in more detail with a member of our staff.

  17. avatar

    Thank you so much for your help. The water from my Berkey is GH 180; KH 120; pH 6.5; NO2 0; NO3 0. I am a little more encouraged after the weekend as the pH has risen to 7.0, the KH is down to 80 (which I have read tetras are happy in) and the fish still seem to be healthy, happy, and active so far. Thank you for the articles which you mention; I will refer to them often I am sure before I finally *get it.* Thanks so much

  18. avatar

    Hi I have three glofish on 10 gallon tank, petsmart recommended me to use distilled water for tank, I have water softer and tested , too much salt PH. It was 9.0 salt pH, so now I’m using distilled water from target, fish looks okay but doesn’t move….

    Do I need water conditioner? Can I use tap water from house which is high salt PH?

    I’m very confusing now, petsmart told me to use distilled water but other said Do Not Use distilled water, it kill fish….

    What do I supposed to do…?

  19. avatar

    Hello M, I do NOT recommend using distilled water. Distilled water has all trace elements and minerals removed so the pH and hardness can fluctuate way too much to be safe for your fish. I’m not sure what you are specifying as “salt pH” but a pH of 9.0 would be far too high for GloFish. I would recommend using spring water instead of distilled or if you used distilled water or Reverse Osmosis (“RO”) filtered water, buffer it first with a product like Kent Marine’s RO Right to remineralize it.

  20. avatar

    Needing help??? I just filled up my 20 gallon aquarium with tapwater is it safe to just let the filter run in the tank with no fish for a week then put my fish in there will the water be safe and all the chlorine be out of the Fish tank by evaporation

  21. avatar

    Hi, the ph level of our well water is high and we do have a water softener but it’s still hard. You recommend a RO system but that might reduce our water pressure. I want to put my Betta fish in a 10 gallon tank. He’s in a 3 gallon right now. I’m thinking the only water I could use is spring water but they are all different as well. What brand name do you recommend to use? Labrador has a demineralized product. Does a Betta need some minerals in their water? I’m so confused and I need help choosing the right water for my little Betta Simon. Thank you

  22. avatar

    Hi, I want to move my little Betta Simon to a 10 gallon tank from his 3 gallon tank and right now he has special Betta water but with the 10 gallon tank I will need to get different water because his special water is in small bottled water. We have well water with a water softener and it has a high ph level of 11. I know Bettas need ph levels between 6.5 to 8 and 7 being neutral would be best. I want to get bottled spring water and I’m wondering if you would know which one would be best. Do Bettas need some minerals, I know they can’t be in chlorinated water right? What type of water is best?

    Thank you,


  23. avatar

    Hi Celine, thanks for commenting! You could use an RO unit. It would give you ~99% pure H2O water, which would be free of the dissolved minerals that cause hard water. Whether you use RO water or distilled water, you would want to ‘re-mineralize’ by adding the good things that are present in water (electrolytes, etc…) that are removed by those filtration methods. Thanks!

  24. avatar

    Hi Celine! You could use water from your faucet and as long as your fish are acclimated to that water properly, they *should* do alright. But if you want to take the next step and provide them with the best water possible…then using distilled water or water from an RO unit would be best. Those types of water are filtered to remove any and all dissolved content, to the point where you have near 99% pure water. When using these types of water it is also important that your fish are acclimated to them as well.

    These are good for removing the bad stuff from water, but they also remove the good stuff like electrolytes and minerals as well. If left alone, your betta would likely survive in this water, but may become lethargic without the pep those elements provide. That is why it is important to add something to re-mineralize or re-energize the water. We carry items like RO Right and Betta Bowl Plus that add those positive elements back into the water and create the ideal environment.

    We hope that helps, please let us know if you have any other questions. Thanks!

  25. avatar

    Hi Bret, thanks for commenting. If you let the filter run for a week, the chlorine will dissipate on it’s own. If you are looking for an immediate solution, something like Seachem Prime or Stress Coat would work. Thanks!

  26. avatar

    Hi thatpetblog, the RO system is not an option for us. Apparently it lowers water pressure. I said that our water is hard but it’s not. The water softener corrects it but our ph level is too high for our Betta. If I want to get him bottled spring water I would have to check the ph level of the brand name but do I have to add a water conditioner and water bacteria in that kind of water for our Betta? Can you recommend a kind of bottled water for my Betta?

    Thank you, Celine

  27. avatar

    Hello Celine, We wouldn’t be able to recommend a specific brand of spring water but most brands should be fine for your betta. The water conditioners recommended in our last reply should be fine for you to remineralize the spring water if needed but always be sure to acclimate the fish to any new water sources carefully.

  28. avatar

    Thank you Eileen. And how do I acclimate my Betta? Petsmart suggests I place him in a bag with his existing water and let him sit in the new tank with the new water for a few minutes. Thank you

  29. avatar

    Hi Celine, Floating the bag only acclimates the fish to the temperature but not to the water chemistry. You can visit our website to view our full recommended Acclimation Procedures.

  30. avatar

    I recently bought a beta fish and was wondering if it is safe to use reverse osmosis water in my 5gallon tank.

    Please get back to me soon.

  31. avatar

    Hello Matt, RO Units are good for removing the bad stuff from water, but they also remove the good stuff like electrolytes and minerals as well. If left alone, your betta would likely survive in this water, but may become lethargic without the pep those elements provide. That is why it is important to add something to re-mineralize or re-energize the water. We carry items like RO Right and Betta Bowl Plus that add those positive elements back into the water and create the ideal environment.

  32. avatar

    Got a new fish tank for goldfish. All of them have died with in the day. We use tetra easy balance and let the filter run before we put the fish in. I know we have well water and thats all i know. What can i do before we get more fish

  33. avatar

    Hello Candis, I would need some more information before I can answer that question for you. How large is the aquarium? How large were the goldfish and how many did you add? How did you acclimate the fish before putting them in the tank? Have you tested your well water, and to start with, what were the values for hardness, pH and temperature? It isn’t unusual to lose fish in a new tank (see our blog “The Nitrogen Cycle and Conditioning Period in New Aquariums”). Goldfish produce a lot of waste and can exaggerate these effects, especially if the aquarium is very small or the goldfish are large. Also, if the fish aren’t acclimate to the tank properly, they are less likely to be able to handle the stress and shock of a new environment (see our recommended Acclimate Procedures for more information). If you would like to speak with someone about your tank in more detail, you can reach our Fish Room staff at 717-299-5691.

  34. avatar

    I have a 50 gallon reef aquarium and currently do my water changes using distilled water. It is such a pain to buy and lug all those jugs of water around. I thought about an RO system but I believe it produces a lot of waste water and most of the ones I have looked at for my aquarium, say not to use it for drinking water. I’d really like to be able to use whatever system I buy for both my aquarium and for drinking water. Have you heard of the Berkey water filter/purifier? This seems like it would do both but I’d like another opinion before I invest in it.

  35. avatar

    Hello Shelby, RO units will produce some waste water but it shouldn’t be “a lot” by any means. If the unit is producing a lot of waste water, there is likely something wrong within the unit or membranes. The RO Units that we sell for aquariums are generally speaking the same units sold for home use for drinking water. Most RO Units will not advertise water as being safe for human consumption because all of the minerals and trace elements have been removed, not because the water is necessarily toxic in any way. I’m not familiar with the brand you mentioned but if water is safe to drink, it should be safe for your aquarium but every unit is different and you will want to take into consideration the membranes and type of filtration used in the unit as well as the water source you are filtering. For more information on RO units and membranes, check out our blog “So, You’ve Got Questions About Reverse Osmosis Water?“.

  36. avatar

    I have a 10 gallon tank I have tried everything to stop the water from turning green I had the water tested at the pet store the tank only stay clear for about 2 weeks

  37. avatar

    Hi Stephanie, Have you tested the Phosphate level? Green water is a classic sign of high phosphates. In addition to testing the level in your tank, I would recommend testing the level in your source water as well (ie. out of the tap if you are using tap water). Some areas have high phosphate levels right out of the source, especially if you are using well water or in a highly agricultural area. If you discover you have high phosphate levels after you test, there are different types of filter medias that you can use to help eliminate it, and you may want to change your water source if those levels are high. Also, making sure your lights aren’t too long should help control the algae; stay below about 8-10 hours.

  38. avatar

    hello, my oldest(4+ years) KOI died last night … a little later my goldfish did the same , I quickly removed the three remaining KOI out of the 20 gallon tank and this am started the cleaning process. I use city(small town) water and am considering “SPRING WATER”. I do use purifying chems minimally with the right measures …. SPRING WATER good ? my largest KOI is 9+ inches the smallest is 2-3″ …. I do not want them to go “BELLY-UP”… help wanted

  39. avatar

    Hi Tracy, A 20-gallon tank is really too small for even one goldfish and definitely not for any koi. Koi need large ponds especially and shouldn’t be kept in an aquarium unless it is at least a few hundred gallons. Dechlorinating tap or municipal water will help – make sure to get a dechlorinator that neutralizers both chlorine AND chloramines – or spring water will be suitable as well but neither will make much of a differences in an overcrowded aquarium.

  40. avatar

    Hi, I have well water that ph comes out of tap at 8.2 and after an hour or two ph drops down to 7.0 , I worry about the ph dropping so quickly may hurt Betta. My tank is 3 gallon and I was using spring water but it got to be expensive for all the water changes. I would leave well water sit out for awhile before adding it but our house gets cold and I try to add same temperature water as tank which is 78 F. Do you have any ideas on what I can do about the high PH right out of tap?

  41. avatar

    Hello Tyra, What is the water hardness? If the pH is fluctuating that quickly, I would guess that your water is pretty soft, meaning that it has no buffering capacity to stabilize it. Adding a buffer to raise the hardness and buffer the pH would help.

  42. avatar

    Thank you SO MUCH for your reply, this has been pretty frustrating to me as you can imagine lol. I don’t want to add in 8.2 ph water so I’ve been adding 2 drops of ph down to water that I add which isn’t really good idea I dought, to try and make ph closest to aquarium water 7.2 , when adding and then someone told me to add a little baking soda couple hours later to keep it from going down too low. So it goes down to about 7.2 and stays there until next water change. I don’t know what else to do to lower ph to match aquarium water during water change. I’ve done water test in bucket and it goes from 8.2 to 7.2 in a few hours on its own with no additives. I only use Prime in aquarium and keep tanks very clean. I’m not sure what the tap water hardness is, is that the gh and kh? Should I get a test for that and how do I buffer the water that comes out of tap without using ph down, I would like to stop using that. My poor fish! Lol

  43. avatar

    Hi Tyra, Adjusting the pH before you put the new water in your tank is a good idea. I would definitely recommend testing your tap water hardness so you know how best to adjust it. GH and KH are both important, but KH is going to play a bigger factor in this situation for stabilizing the pH (the “buffering capacity”). If your KH is low, you can use a buffer like SeaChem’s Neutral Regulator or Alkaline Buffer to help stabilize it. In my experience, these products work more reliably than ph Down or pH Up to stabilize hardness and pH.

  44. avatar

    Ok, thank you so much! You have been such a big help!

  45. avatar

    Hi I’m wanting to set up a small tank with some good fish and bubble eyed gold fish I was wanting to know what type of water I should use .

  46. avatar

    Hello Faith, Goldfish should have a pH between 6.5-7.8 consistently. They also need a large, well-filtered tank to be able to handle the amount of waste they produce and don’t do well in smaller aquariums. This Goldfish Species Profile from our website and these other Fancy Goldfish articles from our blog may help you.

  47. avatar

    Hi,my well water has very high amounts of iron,i wont drink or use it so i buy spring water treated with micron filtration,ozonation, and ultraviolet light.i was wondering if water treated this way is healthy for fish tanks as i only see info on RO treated water?.also the source of water is springbrook springs ,east concord,bottled by mayer bros apple products 3300 transit road ,west seneca, NY 14224 if that info helps.ive not tested my tank yet for nitrate/nitrite, ph, kh ect. yet but i do plan to however my goldfish seem to be happy and moving about,i maintenance with jungle start zyme and aquasafe monthly and i keep a anubus plant and a driftwood in tank and water is well agitated with 2 carbon filters running each side of tank and a air pump and a pleco keeping the place clean (driftwood and veggie rounds seem to always keep pleco satisfied and ive never seen him bother the goldfishes for their coating or anything like that)just mentioning extra info if it helps.

  48. avatar

    Hello Max, Spring water and bottled water sources are generally fine for aquariums.

  49. avatar

    Thank you for this tremendously helpful article.

    Should we expect the well-known brands of spring water to have consistent parameters from one bottle to the next?

    If purified water with added minerals and buffering is the better way to lock down your water source, how does getting to your desired pH and KH work? I’d want to get to 7.0 pH and at least 6 KH.

  50. avatar

    Hi Lou, I would expect major brands to have some consistency but you can contact them directly to see if they can provide you with that information or still test the water before you use it to be sure. If you are using distilled or Reverse Osmosis-filtered water, an RO/DI additive like Kent’s RO Right will remineralize the water or a suitable buffer like SeaChem’s Alkaline Buffer to raise the hardness and alkalinity.

  51. avatar

    Thanks for your answer. I decided to go with purified water and RO Right. From what I’ve read, the pH will probably be around 6.8, which is fine. My current tank’s pH is 7.4. Is there a reliable way I can gradually lower my current tank’s pH over the next few days to prepare my betta for the new water?

  52. avatar

    Hi Lou, You’re welcome! Acid Buffers will lower the pH but can be tricky to target that specifically. I would recommend just using an Acclimation Procedure like this one from our website when moving your betta from the old tank to the new tank since that difference isn’t too extreme. Bettas usually handle changes like that pretty well and should be fine if you do a gradual acclimation.

  53. avatar

    I just started a new 20 gallon aquarium about a week ago and have mollies in there, at first everyone was doing fine but in the last 3 days or so I’ve had 3 fish die. I noticed the water smells slightly sour and its made my brand new filter turn brown already. My water here is really hard so I don’t know if that has something to do with it or not. Is there any suggestions that I could do water wise?

  54. avatar

    Hi Sam, Water hardness will generally not affect fish directly or cause brown water. The first step would be to test the water quality. Knowing your water parameters is like taking vital signs at a doctor’s office. What are the levels for Ammonia, Nitrite, Nitrate and ph to start with? Without knowing those levels, I can’t recommend a next step to you. Also, how many mollies did you have in the tank when the problems started? All new tanks will go through a cycling process and it isn’t unusual to lose fish during that time as the tank will experience spikes in Ammonia, then Nitrite, then Nitrate as the tank becomes established. The more fish that are in the tank, the higher these spikes will be. You can read our blog entry New Tank Syndrome In Home Aquariums and our article Explaining The Nitrogen Cycle for more information.

  55. avatar

    I have a 20 gallon aquarium with 4 KOI ranging 9″ to 2 ” and 2 cichlids (breeding pair w/no fry((kids) I use soft tap water I add AQUA-SAFE chems …. after a few days the water gets cloudy then will turn green . the tank has gotten clear (after a month & 1/2) but NOT recently …. am I not patient enough ?

  56. avatar

    Hello Tracy, Twenty gallons is too small by far for koi and most cichlids and koi and cichlids are generally not compatible together. That tank is overstocked by far and it will be practically impossible to resolve water quality issues with that many fish that are that large in a tank that small. Green water is usually a sign of high phosphate levels which can be removed through filter medias but I wouldn’t expect the tank to be able to clear up and become properly established with those fish.

  57. avatar

    Hello. I’m planing to start 12 gal nano reef tank. Is “great value ” purified water from Walmart going to work for a start??? It said on the bottle: processed by: micros filtration, UV light , reverse osmosis and 0zonation. I just want to do right things from the beginning to avoid algae growth and other issues

  58. avatar

    Hello Miloya, Since you are doing a saltwater tank, that purified water would be fine once it is mixed with the salt. That would fall under the “Reverse Osmosis (RO) and De-ionized (DI) Water” section discussed in this blog.

  59. avatar

    Hello. I am planning on starting a small Aquaponics system indoors. I have well water that has way too many metals to be safe for fish. I need to buy bottled water and I was wondering if you had any idea which brand is best to use?

    I know bottled water is not preferred, but at this point I have no choice if I want to go on building this system.


  60. avatar

    Hello Laura, I wouldn’t have information on what brands available to you would be best. Bottled spring water should be fine to use but avoid distilled water unless you are remineralizing it with a product like Kent Marine RO Right first. Most home Reverse Osmosis system should make water safe enough for aquarium use as well and should be remineralized with the same type of product before use.

  61. avatar

    Q : do “baby” cichids need special food ? … will the parents eat them ?

  62. avatar

    Hello Tracy, Both of those questions would depend on what type of cichlids you are referring to. Most cichlids will not eat their own young but other cichlids in the tank may.

  63. avatar

    I have a pure water system installed on my kitchen tap I just cleaned tank and filled with filtered water will this hurt or help my two goldfish

  64. avatar

    Hi Maureen, That would depend on what type of system your “pure water system” is. If it is a Reverse Osmosis/De-ionized Water (RO/DI) system that is discussed here, you need to remineralize the water before adding it to your tank. Not doing that will allow the water parameters like pH and hardness to swing drastically and can be very harmful to your fish.

  65. avatar
    sumit manchanda

    Does Bottled mineral water need to be remineralised before using

  66. avatar

    Hello Sumit, Spring water sources usually don’t need to be remineralized while distilled water does. If it is being used in a freshwater tank, it is always a good idea to test the hardness and pH before use if you are uncertain and buffer as needed.

  67. avatar

    Can I use spring bottled water for a 1 gallon tank for 3 glofish?

  68. avatar

    Hello Shane, As we discussed in this blog, spring water is generally acceptable for aquarium use. However, a one-gallon tank is really too small for GloFish. The very smallest tank I’d recommend for GloFish Danios would be 5 gallons and even that is fairly tiny.

  69. avatar
    Paulette Nichole Maples

    Hi i have a gold fish and a calico fantail goldfish in a 15 gallon tank i need to do atleast a 25%-50% water change can i used distilled drinking water i also still have the conditioner that came with the tank my husband says i can use the distilled water but everything i find it says no so im a bit confused
    thanks paulette

  70. avatar

    Hello Paulette, You should NOT use distilled water in an aquarium as we discussed above, especially in a tank like yours. Distilled water has all of the minerals removed that would help keep the basic water chemistry stable and that would especially be a problem in a goldfish tank. As I’m sure you are aware, 15 gallons is far too small for goldfish and the amount of waste they produce and using distilled water would amplify the water quality issues from all of the Ammonia and food waste. Ideally, I would definitely recommend upgrading the tank size to AT LEAST 30 gallons or more and only doing 15-20% water changes once or twice a month. Spring water would be a better water source choice than distilled water. You can find more information on goldfish care in our articles The Best Aquarium Filter For Goldfish, How To Care For Carnival Fish and our Goldfish Species Profile.

  71. avatar

    Hi …. I live in southern NH … I have tried two times in two different 20 gallon tanks … I have well water with a whole house filter it removes sulfur smell and other particles. It is a true artesian well the water runs full time into an over flow pond… any way both times I have used my water from my tap …. and I end up with bad “pea soup” algae that I can’t get rid of … the fish live fine .. but the algae is out of control….the room does get direct sun in the morning….is it the sun? Should I be using full spectrum bulbs? Can I use a Britta filter to fill the tank or a pure filter pitcher? Where is the algae coming from??? I use a filter for a 40 gallon tank the 40 dollar pet store waterfall filter that hangs on the back of the tank………. the algae is killing me tried every chemical in the book……thanks any ideas?

  72. avatar

    Hello Dean, Green water is almost always a sign of high Phosphate levels. Well water sources are especially notorious for Phosphates since wells tend to be contaminated with it due to fertilizers from farms and gardens. I would recommend testing both your tank and your source water. Phosphates aren’t removed by carbon or carbon-based filters like Brita cartridges so if your source water level is high, you may want to consider using a different water source for your aquarium, using an RO/DI filter or using a Phosphate-removing filter media in the aquariums.

  73. avatar

    hello, I was wondering if someone could please help me, with my water problem in my 125 gallon goldfish tank with 4 fancy tail orandas, the problem that I am having is , out of tap my ph is 7.2 / 7.4, and in my tank it’s 8.0 / 8.2 , gh and kh are fine , the problem is that I have well water that had alot of iron in it , the water is very hard, so I half to airrate the water for 72 hours before adding it to my tank, and then the tubs I hold the water in, you can see the iron build up stains on the sides of the containers, I also scrub them each week with just water , before adding fresh. since my ph is so high if I clean my filters just a little to much I’ll also get an anommia spike, even tho I have 2 fx6s on this tank, I have 2 cuz, I had oscars in there at one time , that I rehomed.now with the water, I use prime as a water condition, but I was wondering if there was any thing else I could use to help with the iron as well, or is prime enough, how should I treat the containers that I hold my water in, should I dose them with prime and like that sit in the container the 72 hours , right now I am just adding the prime before I add the fresh water. ,I am at a loss here, I just want the best for the fish, I thought about a RO, unit but I don’t understand about buffing and what you half to put back in to the water for goldfisg , cuz they like hard water , and I’m a fair that it would mess with the ph, gh and kh,

  74. avatar

    Really need to know what is the best product to get to remineralise RO water for Betta and tropical fish. There’s so many I really don’t know which to get our of I’ll need a combination is product. My tap water is pH 7.8 GH 3 KH 1. I think it’s PH too high and GH KH too low. Because KH so low PH swing is happening. I have RO unit which I remineralise for shrimp keeping but with the fish not sure what to get to remineralise it.

  75. avatar

    Hello Melon, The same product you use to remineralize for shrimp can be used for fish.

  76. avatar

    Hi Lisa, It sounds like there may be a couple issues going on here that aren’t necessarily related. If you’d like, you can contact our staff directly at 717-299-5691 so we can discuss your tank more specifically.
    For the high iron levels…this isn’t something that aerating water would address or that would really be tied to hardness, pH or Ammonia. A water softener would help to remove some of the iron but it isn’t necessarily what it is targeting. If you are using carbon in your filter, that would help remove any heavy metals like iron but should be changed frequently (every 2-3 weeks if your levels are high). An RO unit would also help to remove impurities like iron and the water would just need to be treated with a buffer like RO Right before being added to the tank. If your hardness is suitable, you can use a freshwater buffer like Neutral Regulator to control the pH. Prime will help to detoxify Ammonia, Chlorine and Chloramines but it isn’t a water conditioner and isn’t going to affect the Iron.
    For the Ammonia spike you mentioned…regular aquarium maintenance shouldn’t cause an Ammonia spike in a healthy, established tank. What are you doing for this maintenance when you see a spike? What in the filter are you changing, and how much water are you changing at a time?

  77. avatar

    Hi Melon, Yes. That product will do the same thing to the water no matter what animals are going into it. If that is giving you the results you want in your shrimp tank, it will give those same results for your betta tank.

  78. avatar

    Oh wow that is awesome. People were saying I need to get so many chemicals. Like seachem alkaline buffer, seachem equilibrium and some other things. I was like why is there so many shrimp mineral brand that will do it all with just 1 product perfect for shrimp yet I need 10 million chemicals and stuff for fish. Great to know that shrimp mineral actually works for fish. *Thumbs up*

  79. avatar

    Hi Melon, The only difference between some of the products targeted for shrimp is that they may have higher iodine levels to help with the shrimp’s shell formation and molting. Otherwise, it is usually very similar to general aquarium products and the higher iodine won’t harm fish. If you ever have questions about a specific product being safe for fish, we would always also recommend contacting the manufacturer directly for those specific questions. Most brands should have customer service contact information on their labels or website.

  80. avatar

    hello Eileen, and thank you for your help, the reason why I airrate the water before I add it to the fish tanks is because the ph doesn’t match the tanks ph , I do use carbon in one of my fx6s on the tank ,and I also use ploy filter in the other fx6 , i have 2 on this tank for filtration, I figured out why I was getting a reading of amonnia of .25 was because I left the tank sit empty for 2 days before I added my goldfish, and some of the beneficial bacteria had died off, what happened was I had oscars in this tank and I rehomed them, I decided to put my orandas in this 125 gallon that the oscars were in and then get more orandas , I added the orandas 2 days later only because I needed the temperature to drop from 79 degrees to 74 degrees and that took 2 days to do cause it has been so hot here, so after the 2 days I added 2 goldfish and then I got the amonnia, I also cleaned the filters before I added them so I thought that’s why I got the amonnia also, I wasn’t sure what was going on cause the tank has been cycled for the past few years, after a week I added 2 more orandas and waited another week and added 2 more , now I have a total of 6 orandas in this 125 gallon tank everything is going good so far, my ph is 8.0 , gh is 179, and kh is 107.4 the problem I have is the iron in the water , I am looking for something to put in my fx6s that will help filter the iron out , I have thought about the RO/DI filtering but what I don’t understand is how do I keep my ph the same, and how much of the buffer do I add, how are my fish going to adjust to the change of the ph , and I do even understand how to use any of that buffer stuff, I want the best for the fish, but I also don’t want to make any changes to them that I don’t know how to do right and hurt them or even kill them, I would be heart broken, I change my carbon every 3 weeks , and I only use it I the one fx6, I use fluval carbon they come already pretty packed in little bags, I use 3 of them, in the other fx6 I use poly filter the one that changes colors, to let you know what it’s pulling out of you water , and this is my first time useing it , it’s only been in the filter for a few days, I also use it in my betta tanks in the filters and it’s is turning brown already, I was wondering if there is another good product that I could try, I also might try and find someone to see if they can come to my house and help me and teach me on how to do the RO/DI unit, and how to mix the right amount of buffer, I think that would be best cause I do not know what else to use it my filters that would help. I have tried so many things I also tried purge from seachem, I use alot of there products , I was thinking about trying seachems cuprisorb have you ever heard of it , I emailed seachem and they said that it would be ok to use it with carbon , and that it will not change my ph, gh, or kh, but I haven’t tried it yet,, I’m not sure of what else to use , my live plants in the tank are growing fine and I don’t add nothing to the tank for them , I just got a good light for them made by fluval, they are all low maintenance plants ,plus I have some pothos plants growing out of the top of tank in back,I also do 50 gollon water change in the 125 gallon tank each week I feed new life spectrum gel food and sinking pellets, and alge gel , alge pellets, seaweed, peas and other veggies, each week I test the water for nitrates and ph and amonnia, nitrates are always around 15/ 20ppm, maybe it’s hard to tell I use apl test kits, do you think that the nitrates are to high after a week, I thought about doing another water change during the week also , but some people say the 15 / 20 isn’t high , and the once a week water change is fine , so sorry for asking you about so many things, I don’t know alot about fish , yeah I know about cycling a fish tank and all, my first fish is a fish from petsmart and I only got him cause he was dieing , I saved him, I had a 30 gallon tank at the time and it wasn’t cycled only cause I had no idea that I would be bring a dieing fish home with me that day, I used stability from seachem and cycled that tank, I made sure that I tested that water every day , and treated with prime when I needed to, he got better with in the first 2 days I had him and he is still with me today 3 years later, so maybe I am doing something right, but my water here still is junk, any way thank you once again for your help have a great day,

  81. avatar

    Hi Lisa, I would recommend calling and having a conversation about your tank with someone at our store. It sounds like there may be some things about your tank that are getting lost or confused between what you are experiencing and what I am understanding from your comments. I’ll try to touch on some of the key points that stick out to me here, and some of the articles in the Aquatic Article Archive on our website might help you understand more about your aquarium and how to best care for your fish.

    -pH: Aerating water isn’t going to have a significant or permanent impact on pH. It may change it slightly while the bubbles are agitating the water, but it doesn’t do anything to the chemistry of the water. If the water in your tank is much higher than it is out of the tap, make sure you don’t have any ornaments or substrate in the tank that raising pH like crushed coral or some other natural rocks and materials.

    -RO water: Switching to RO water would drastically cut down on your iron issues but would have to be remineralized before adding to your tank. You can use a buffer to do this, which all have directions on them and can be added to the buckets you mentioned for the new water before you add it to your tank.

    -Water changes: The Ammonia issues you are seeing may be due to your water changes. Changing 50 gallons of water every week (almost half the water) is essentially restarting your tank every week. Those changes are very large and are going to remove most of the beneficial bacteria that takes care of waste so your tank needs to go through its cycling process all over again. For any tank, you would want to wait until the tank has finished cycling before starting any water changes, and then stick to changing no more than 15-20% once or twice a month. The 0.25 Ammonia reading you saw when changing the tank from Oscars to Goldfish was more likely because the tank was trying to cycle rather than because the bacteria was dying off.

  82. avatar

    Hi i want to have a question to ask u um is what is the best water that suites goldfish?
    please reply soon

  83. avatar

    Hello Jordan, Water hardness isn’t important for goldfish but they tend to do better in hard water since the pH can’t change as much as in soft water. The pH level should be consistent and between 7.0-7.8.

  84. avatar
    Rafael Gutiérrez

    Hi, I would like to know if Zephyrhills spring water from Florida State is ready to use for a fish tank. I use this water at home and I’m looking for a ready to use water, with no treatment to fill my tank.


    Rafael Gutiérrez

  85. avatar

    Hello Rafael, It looks like you can get an analysis of their water parameters and mineral content on their website, https://www.zephyrhillswater.com/faq . You would need to test the water to determine if the pH and hardness are where you need them for whatever types of fish you want to keep or if you need to buffer it to get it to the proper levels. All fish, plants and inverts have different needs for parameters like pH and water hardness.

  86. avatar
    Brittney Gulsby

    I have a glofish danio can I use watwr from a spring?

  87. avatar

    Hello Brittney, That is difficult to say without knowing more about the water parameters of it. What is the pH? Hardness? Nitrates and Phosphates? If the chemistry of it matches what you would like in your tank and it is safe as drinking water, it should be safe in your tank.

  88. avatar


    I am trying to set up a 3 gallon tank for one betta for the first time. I have read tutorials online and have researched what I should need. I have a low setting filter and heater and lots of other stuff that I have purchased. I want to make the most natural environment possible. I also am going to be using substrate, and I want to set up my tank and have everything in it and running for a while before I introduce my Betta. I’m not sure what type of water I could use that would be best. I could use well water from my parents’ house, tap water from mine, or buy another type if I need to in order to establish a good environment early on. I’m going to add in a live plant before introducing my betta, and I want to make sure that I have a healthy water environment before resorting to adding a one-fix-all neutralizer or supplement mix. I’m trying to make sure that my tank is working before I introduce my Betta. Any advice? Thank you!

  89. avatar

    I have two tanks:

    1) 20 gallons gold fish
    2) 55 gallons tropical

    My tap water is 7.4 ph but after a day or so it goes to 8.4 PH.


  90. avatar

    Hi Jeff, What is the Carbonate Hardness (KH)? If this is high, then it would be very difficult to change the pH in the tank. Also, certain types of decoration and substrates like crushed coral, aragonite and some types of rocks will raise the hardness and keep the pH very high.

  91. avatar

    I set up a 20 Gallon freshwater tank a little over a month ago, and I have been cycling ever since. I have not introduced any fish to my tank because I don’t want to risk harming them or giving them a bad life just for the sake of cycling my tank. I test my water very often, but the Ammonia levels simply won’t budge (it hasn’t gone below 0.5 ppm). When I test my tap water as is, it comes out to about 0.5 ppm as well. I’ve conditioned the water and used the API Quick Start to try and build up the beneficial bacteria, but I haven’t seen any progress.

    I’ve thought about adding one or two fish and using the API Ammo Lock, so that they can help build up the beneficial bacteria while not being harmed by the Ammonia, but I’m hesitant.

    Research says if the ammonia levels are high, you should do a 10% water change, however if my tap water has the same ammonia levels, I feel that it won’t make a difference.

    What is something that I can do (or what is the best water to use) to lower my ammonia levels so that I can finally get some fish for my tank? If possible, I want to avoid adding fish at all costs if it means that they will be harmed in any way, or have poor quality of life.

  92. avatar

    Hi Jenna, It is very unusual for tap water to consistently have a high Ammonia reading. Is your tap connected to a well or a municipal water source? Do you know if it is treated with chlorine or chloramines and at what dosage? Are you using a liquid test kit or test strips? Test strips are notoriously inaccurate once they’ve been exposed to air. I would recommend possibly having your water conditions doublechecked…most fish stores including ours or even swimming pool stores will test water for free. If your water source does indeed contain Ammonia for some reason, a filter media like zeolite should remove it or you can switch to a different water source like spring water or an RO/DI Unit. That said, Ammonia should reduce on its own once the tank is cycled. You can view some Fishless Tank Cycling Instructions on our website to cycle your tank without adding fish. The Quick Start you have been using should be adding the bacteria described in those instructions, although I prefer MicrobeLift’s Nite-Out II as a bacterial supplement in my experience.

  93. avatar

    I only use spring water in my tank. Wondering if I should be doing that.

  94. avatar

    Hi Linda, Spring water is in general fine in most aquariums.

  95. avatar

    Can we use our drinking water for aquarium

  96. avatar

    Hello Anonymous, Most drinking water is fine but like we discussed here, you would need to test it to make sure since “drinking water” is an incredibly broad term. Some municipalities treat with Chlorine and chloramines or may have high Nitrates or Phosphates that wouldn’t be safe for your tank, or if you are using distilled or RO/DI water as your drinking water, it would need to be remineralized.

  97. avatar

    Hello I was given 2 fish yesterday by a relative… one is a gold fish & I am not sure what type the other is, but the goldfish is huge! She tells me that she has always used spring water to fill this 10gallon tank. I am was wondering would it be safe if I used city water instead? I don’t wanna kill them but I used to have fish and I always used city water and they lived a long time over a year or so and got really big even the algae eaters. Please let me know what I should do … thnx!

  98. avatar

    Hi Alexis, Most importantly, a 10-gallon tank would be far too small for even one goldfish, without even knowing what kind of fish the other one is. If you need help identifying that one, you can send us a photo at fish@thatpetplace.com and we can help with that. Fancy goldfish like Fantails, Orandas, Moors and others should have at least 30 gallons for one fish and the common Comet Goldfish like those sold as “feeder fish” or often given away at carnivals grow to close to a foot in length and should have at least a 100-gallon aquarium or, ideally, a pond. For more information on aquariums for goldfish, you can check out our blogs The Best Aquarium Filters For Goldfish and http://blogs.thatpetplace.com/thatfishblog/2008/05/15/carnival-fish-part-1/#.XDyXZvkrJPY to start with.

    That said, using “city water” depends on your “city water”…every municipality is different and may treat their water differently. Most use chlorine or chloramines to sanitize their water so you would want to use a water conditioner to neutralize them before adding it to the aquarium. You can contact your local water authority if you aren’t sure what is used in your area and be sure to get a water conditioner that neutralizes BOTH chlorine and chloramine if your water is treated with both (most are nowadays); some water conditioners are only good on chlorine. You would also want to test the pH and carbonate hardness (KH) out of your tap to make sure it is an appropriate level for your fish and adjust accordingly if it isn’t. If you have any other questions or concerns, feel free to contact our Fish Room staff at 717-299-5691 or email the address above.

  99. avatar

    Hi there! Long time aquarium keeper who is wanting to step into the world of salt water! I typically just use my tap water with prime conditioner in all of my fresh water tanks, and it works great. My only issue is that my tap water has a natural nitrate reading between 10-15 ppm, which really isn’t an issue in my fresh water systems, just do more frequent water changes. My concern is that it is to high of a starting point for a salt water aquarium. I’m only keeping a 20 gallon to start, so I was thinking of using distilled water in this application. If I understand correctly the salt should correct for the imbalance of the distilled water? Or would I need to add an additional buffer to make up for this? And help is gelreatly appreciated! Thanks!

  100. avatar

    Hi Jesse, The salt and other minerals in the salt mix would buffer the water. If you get into some more advanced corals, you may need to dose extra supplements but otherwise, the salt and RO water is fine.

  101. avatar

    Hi there – I have been having an ongoing water quality issue in my tank. We started with a 5 gallon tank with 5 fish (mollies & platies). I let the tank cycle before putting fish in, added fish two at a time to try to avoid an ammonia spike, used tap water initially (treated with Start Right) and the water was still showing very high ammonia levels and very hard water (which is strange because I treated the tap water and we have a water softener). Over the past three months I have done 25% water changes about every two weeks, then switched to doing it once a week. I was told not to vacuum the gravel so I do not take out the good bacteria from the tank. The ammonia still remained high and hardness as well. Then I upgraded to a 10 gallon, still only 5 fish. To fill this tank, I used about 3 gallons of the tank water from the 5 gallon so the fish weren’t going into completely brand new water, two gallons of purified water, and 2.5 gallons of tap water that I treated with Start Right. I also ended up cleaning 50% of the gravel before moving it into the 10 gallon aquarium. I left the other 50% uncleaned as to not disturb all of the good bacteria. I cleaned 50% of the gravel because I noticed a decent amount of fish food in the gravel, where the fish/snail could not reach it to clean it up. So, now I have this 10 gallon (have not added any new fish, still only have 5), it is STILL testing high ammonia and testing as very hard water as well. I am at a loss. I don’t know what to do anymore. I have ALWAYS had fish tanks and have never had such a hard time with this. Any suggestions would be greatly appreciated as we keep losing fish 🙁

  102. avatar

    To add to my previous comment – I am using test strips to test the water.

  103. avatar

    Hi Rachel, I would recommend calling us and speaking with someone about your tank so we can have a conversation and get into more detail than I can here. You can reach our Fish Room staff at 717-299-5691, option 6. You can also email fish@thatpetplace.com if you aren’t comfortable calling. A few things to look at in the meantime:
    -You mentioned that you cycled before adding fish…what did you do to cycle the tank? Did you add bacteria at all or just run the tank with a filter? Without adding fish or bacteria, the tank wouldn’t have cycled or gone through any changes from the tap water you originally added. It would only have started cycling then when you added the first fish, causing an Ammonia spike at the start of the cycle.
    -How far apart did you add the two fish at a time? If it was too close together – wihin a week I’d say for a tank that small – the bacteria population probably didn’t get a chance to catch up with the waste being produced.
    -What type of decorations and gravel do you have in the tank? Some types of gravel and rocks will raise the pH and hardness.
    -You would want to at the very least stir up the gravel during cleaning. Better still, use a gravel siphon to remove any fish waste and leftover food from the gravel. This shouldn’t remove much good bacteria, and it would get rid of the waste so it doesn’t decompose and produce Ammonia.
    -I would recommend getting liquid test kits or having your water checked using liquid kits. Test strips are notoriously inaccurate and will start to become less accurate as soon as the container is opened and exposed to the moisture in the air.

  104. avatar

    i have a 6.8 gallon tank with a blue lobster. Can I use bottled water like Poland spring for it?

  105. avatar

    Hi Nathan, Are you referring to a saltwater lobster or a freshwater crawfish? For freshwater, spring water is usually fine but if the water is distilled, it should be remineralized before use as we discussed in this blog. For saltwater, the salt mix will remineralize the water.

  106. avatar

    do you need to use water conditioner for spring water tanks?

  107. avatar

    Hello Nathan, You would not need a water conditioner if using spring water. Water conditioners are generally used for removing Chlorine and Chloramines from water, and those chemicals shouldn’t be present in spring water.

  108. avatar

    I have had an African Clawed Frog for two years. I just recently moved and now my water stays cloudy or milky. The water at my two previous homes never did that with any tank I had. Now my frog tank and all my fish tanks are like this. I waited it out like I was told but it’s getting worse. Could you please advice. Thank you.

  109. avatar

    Hi Renae, Have you tested the water quality (at least pH, Hardness, Ammonia, Nitrite, Nitrate to start with)? Have you tested your source water for the same parameters? What size are the aquariums and what is in them? What type of filtration do you have on them? How long has it been since they were set up? Have you been doing water changes on them and if so, how much are you changing and how frequently?

  110. avatar

    Mine doesn’t fall under these categories I used a zero brand water filter to fill a 2 gallon tank and somewhere during filling it the filter took a dive and the water from the filter suddenly taste metallic.
    A zero blog says there are excess hydrogen ions in the water due to ion exchange process used in that type of filter. Idk what that means, is it safe ti put my betta in there or not? That filter brand seems to actually make tap water WORSE when its time to change the filter

  111. avatar

    Hello new betta mom, I would recommend testing the source water out of your tap before it enters the Zero filter and testing the filtered water to see what the conditions are. I’m not familiar with the brand but from what I see online for Zero filters, it looks like they are reported to remove all Total Dissolved Solids. If this is true and the filter is working properly, then the resulting water would essentially be the same as the Distilled or RO/DI water discussed here and would need to be buffered before you use it with your betta. If the filtered water seems metallic, then the filter might not be working correctly, especially if the source water has a high mineral content. I’m not seeing anywhere what type of resin they use in their filter but the “excess hydrogen ions” would affect the pH of the water (the H in pH actually stands for Hydrogen). The FAQs on the webpage for the Zero filters discusses this and it looks like a change in the pH means it is time to change your filter. I would recommend contacting them directly if you have questions about that part or questions on if your filter is working correctly.

  112. avatar

    Hello I’ve never had a fish before I recently got some big gold fish and some baby ones. I have 2 20 gallon tanks. I’ve been using tap water filtering it for 48 hours with a regular tank filter and letting it sit for 48 also using water conditioner in another 20 gallon fish tank before changing the water out. Is their an easier way or should I just keep doing it this way. The fish seem pretty happy.

  113. avatar

    I also have a baby catfish.

  114. avatar

    Hi Rebecca, To start with, a 20-gallon tank is really much too small for even one goldfish, much less multiple, especially if they are common goldfish rather than a fancy variety. They will need a much, much larger tank or pond to stay healthy. That said, the preparation for new tank water depends on where the water is coming from. If it is from a municipal water sources that uses chlorine and/or chloramines to treat it, you will need to use a water conditioner to neutralize it. Letting the water sit will only let the chlorine escape; the chloramines will still be present. You can read our blog entry Treating The Treated – The Line Between Tap Water And Aquarium Water for more information on that. Otherwise, you only need to make sure the water has the same parameters as the tank (pH, temperature, and hardness especially) before adding it to the tank. There is no need for a four day preparation; most of this can be done in a clean bucket as part of the water change.

  115. avatar

    My ammonia level is on the high side, is it correct to assume that pH will be also high. If the pH is indeed high, will it be a silly idea to add vinegar to lower the pH. Kindly advise. Thks

  116. avatar

    Hi Stephen, High Ammonia would not cause a high pH. While the two aren’t really related, a very high Ammonia may actually lower pH since it is acidic. I would’t add vinegar to a tank to lower pH, especially with high Ammonia, since it would likely cause even worse conditions. Since there seem to be multiple issues going on here and I don’t have enough information to make specific recommendations yet, I would recommend calling and having a discussion about your tank and goals with our staff. You can reach the Fish Room staff at 717-299-5691, option 6.

  117. avatar
    Katie Castrovinci

    I have a 2.5 gallon tank with a Glofish betta. I am currently using a store brand spring water that was processed by Ozonation. Will this process hurt my fish? Also,I would like to switch to Poland spring water for my fish but in the analysis online it shows fluoride, sodium, and magnesium present in the Poland spring Water …. will this harm my fish? I can’t use my house water as I have a well and it would not be very healthy for my fish. Would water conditioner added to the Poland spring water help these issues?

  118. avatar

    Hi Katie, Either spring water source would be fine for your fish as long as it isn’t distilled water like we discussed here. You shouldn’t need a water conditioner with spring water if it hasn’t been chlorinated or treated with chloramines.

  119. avatar

    Will ozonation processed water hurt my fish?

  120. avatar

    Hi Katie, No, ozonation will not hurt your fish.

  121. avatar

    I have a question about well water an distilled water mix ratio. I have to mix it cause we use well water for drinking, it is filtered at the pump. My question is our aquarium store is closed an I dont remember the ratio to tap water to mix it before adding to tank

  122. avatar

    We set up a 15 gallon tank in December, put in plants and have had it running all this time without fish. Every time we think we’re ready to buy fish, we hit another roadblock. We were going to get neon tetras, but were told our water’s too hard, so we decided on guppies, but were told that the ph is too low (ph 6.4) and that the guppies would not survive in well water. We have to rely on websites and phone calls to stores around the country because except for Petco, there is not a aquarium store within about 90 miles. We have well water that is very hard. We have considered using bottled spring water, but were told that we would need to add minerals. Could we use a 50/50 mix of well water and bottled spring water to dilute the hardeness, but retain some of the mineral content? We have a bad case of analysis paralysis. Please help.

  123. avatar

    Ho John, Figuring out parameters can certainly be confusing. I’m surprised to hear you say that you have low pH and hard water…that is certainly unusual since the minerals that make water “hard” usually buffer the pH at a much higher level. What are the actual values for your water hardness (KH and GH)?

    If you are using SPRING water, it typically doesn’t have to be remineralized like DISTILLED water would. If you are considering using spring water (not distilled water), I would recommend testing the pH and hardness levels to see what you are starting with. Distilled or RO/DI water, however, would have had all of the minerals and trace elements removed during the filtering process and would need to be remineralized or buffered as we discussed in this blog.

    As far as the “safety” of well water…that can vary. Are you in a very agricultural area with lots of farm or garden runoff? This can cause the Phosphate levels to be high and may cause algae issues in your tank. Do you know if your area has a lot of limestone or other easily-dissolved minerals in the ground (ie, do you have a lot of quarries or problems with sinkholes?)? Those minerals can affect the water chemistry in your well. The best way to tell if mixing your sources is right for you is to actually do it in a bucket or other container and test the results to see if that falls into the range you’d like but generally speaking, spring water is fine to use and RO/DI or distilled water is only safe if it is buffered or remineralized.

    If you would like additional help, feel free to give our staff a call at 717-299-5691 (option 6) or email us at fish@thatpetplace.com so we can discuss and go into more detail than I can here. If you can have the values for pH, KH and GH for each of the sources you are considering when you call or email, that would be helpful.

  124. avatar

    Eileen, Thanks for getting back to me so soon. I guess part of my problem is that I didn’t know I would need a degree in chemistry just to have some fish in my living room. We live in southern Delarware, and even though we live in a wooded area, the wooded area is surrounded by chicken farms and cornfields, so I guess phosphates might be an issue. We’ve decided to start using bottled spring water. Since we’ve had the plants in the tank of well water for nearly 2 months, should we gradually switch over to bottled water, or is it OK to siphon all the water out and start over with spring water?

    Thanks again.

  125. avatar

    No chemistry degree needed…just some simple test kits. Most aquarium stores test water as well. You can check at your local stores since you are a bit far (and outside of PA) to visit us but I would recommend asking them to test using a liquid reagent test (or getting kits like these API test kits for yourself) rather than using test strips that are notoriously inaccurate. I wouldn’t recommend emptying an established tank since that would mean that you would need to start the entire cycling process over (you can read more about the Nitrogen Cycle here). Without knowing what parameters you are starting with like the hardness, pH and Phosphates, it is difficult to recommend the best steps going forward.

  126. avatar

    I got fish (6 serpae tetras) which seem to be quite happy so far. Should mention that the local fish store suggested adding some nitrifying bacteria, which I did. my water started out marginally hard but now seems to be at the extreme hard level with pH remaining stable at 6.5. This morning I noticed the NO2 level has risen to 1.

  127. avatar

    Hello Henri, Nitrifying bacteria would not affect water hardness. That would more likely be affected by certain types of rock or substrate in the aquarium or by the source water being used. I would recommend reading our article The Nitrogen Cycle and Conditioning Period in New Aquariums for more information on the function of nitrifying bacteria and water chemistry.

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!).