1. L

    LittleCritters New Member Member

    Is it normal for sitting water to slowly develop nitrates? Day one is 0 but increases the longer it sits? Thanks for the help guys.
  2. gsong321

    gsong321 Valued Member Member

    What do you mean by sitting water? Unfiltered...stagnant? I'm trying to picture this but don't quite understand. It's normal for zero nitrates at first but it usually takes some time for it to rise depending on how much decaying material you have in the tank. When the nitrites are gone and the nitrates go up then your cycling. What is the ammonia level?
  3. B

    Bhuij Valued Member Member

    If your tank is already cycled and you have fish, then yes, it is perfectly normal for nitrates to go up over time. In fact, that's the primary reason for water changes in a non-planted, cycled tank with fish. I usually aim to do water changes enough to keep mine below 20ppm when I don't have plants. If I do have plants, I try to keep them between 10 and 20 ppm.