Monkey asked in PetsFish · 9 years ago

Cant seem to get control of the nitrates, and nitrites in my fish tank?

ive tested my tap water it has little to no nitrates and nitrites, yet my tank is super high, like on the test strip the highest color. My fish are dying, my snails are even dying only thins seeming okay are my two frogs and my panda cory.

i had 4 goldfish, down to two. And one is very sick and seems to also have developed tail rot. which I am trying to treat with meds.

Ive just done a 30% water change still high, Ive used prime water treater.

I always clean with a gravol cleaner, and try to get all most of poop and old food,

when all the problem started i did a 40% water change cause the water was dirty. i did this with my guppy tank, and this goldfish guppies have since died, and my goldfish had gradually been dying.I though at first maybe it was due to spring clean, and the city doing water main flushing...since i have never had trouble before. i dont know what to do???


I also have live plants ...i dont know what else to do. if my tap water is reading find for nitrates and nitrites why is my tank having so much trouble?

Update 2:

Hmmmm it just seems werid to me what would be causing it...the tank is clean now, and has been for a week, I did a water change today in a attempt to correct the levels seeing as my tap water is fine. I dont know?!?!

4 Answers

  • Liz
    Lv 6
    9 years ago
    Favorite Answer

    The reason why your tank has nitrites & nitrates is because its cycling (going through the nitrogen cycle). All new tanks cycle when you first add an ammonia source to them, but things can happen to established tanks that can cause them to re-cycle, for example;

    1. Not adding dechlorinator to tap water that goes into the tank.

    2. Cleaning the filter out in water that is undechlorinated.

    3. Over-cleaning filter.

    4. Not having a proper filter.

    5. Overstocking tank (with growing fish bioload becomes to much for beneficial nitrifying bacteria in filter media to handle).

    6. Using medications that kill off beneficial nitrifying bacteria

    6. Not cleaning the tank regularly enough

    7. Doing excessively sized water changes (like over 60%)

    8. Adding too many fish to the tank at once (even in established tank)

    Etc. Please see this link for more understanding & info on maintaining good water quality in your aquarium;

    Fish excrete ammonia. The beneficial nitrifying bacteria in the filter media converts this ammonia into nitrites and then into nitrates. Nitrates are not harmful to fish unless in excessive levels (over 40) but nitrites & ammonia are very toxic to fish and anything above 0 is bad. It is normal to have some reading of nitrates in an established tank though as this is the end product of the nitrogen cycle when it is complete.

    The best way to lower levels of ammonia, nitrites or nitrates is to do regular partial water changes (15-40%) with dechlorinator. In the case of a mature/established tank re-cycling you need to find the cause of it re-cycling as once cycled tanks should cycle again unless something has gone wrong.

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  • PeeTee
    Lv 7
    9 years ago

    When water quality is let go so long that the water even looks dirty or the overfeeding goes on so long as to make the water appear dirty, these conditions cause the pH to drop (called "sour tank"). In this low pH condition ammonia and nitrites are held in large amounts as nitrate. Doing a large water change raises the pH. The higher pH water cannot hold as much nitrate and the excess nitrate reverts to nitrite, which is highly toxic. This is the reason that large water changes should be avoided unless the water is clean to begin with. The dieing snails are contributing to the problem. The way to salvage the situation is to begin doing 10% or at most 15% water changes morning and night. No sudden changes! Do this routine until the tank is clean and stable You will know this when the pH in the tank is the same as your fill water and the nitrites are all gone (0%). Then you can go to a schedule of weekly 20% changes accompanied by careful gravel vacuuming.

    I suspect that you overfeed your fish badly. This coupled with large water changes is a form of "killing with kindness" .

    One other item, the problem and attempted solutions have probably left your nitrifying bacteria colonies in terrible condition also. Be aware that the cycle may be weak. This is a good reason to cut feedings to one very small feed every three days.

    Source(s): 60 years of fishkeeping.
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  • Ysbeth
    Lv 6
    9 years ago

    If your water looked dirty then it was probably filthy. I do not usually tell people to put anything in the tank to clean the water but in your case you may want to ask at the fishstore because your tanks are crashing. Putting some extra carbon in your filter may help and they probably have other products you can try. You also need to continue to do water changes until your water levels are correct.

    However, you need to correct whatever is causing this issue in the first place or it will keep happening. Overcrowding and overfeeding are the usual culprits. Leaving dead plants and fish in the tank will cause problems as well. If the tanks are new this may be happening if they tanks are cycling and you put too many fish in them. The petstore should have some books on aquarium care.

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  • dallas
    Lv 5
    9 years ago

    the only thing i can recommend is to continue doing water changes till eventually every thing will clear up and nitrates/nitrites will go down

    my best guess is that your tank is going through a complete recycle (had this happen to my tank even though it has been up and running for over 2 years)

    also i recommend that you change from using the test strips to using the liquid form of test kit (more expensive but also more accurate)

    Source(s): self 35 years raising fish
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