Quarantine Tank Cycling- Zero Nitrates

[Kurt_Nelson]

Originally Posted by roka64

... I would say, if you have nitrAtes present and no ammonia or nitrItes in your main, you are good to go and can seed the biowheel in the main.

I can think of a case where that wouldn't be true.

You cycle the main tank, see the ammonia and nitrite spike and then go to 0.0 ppm, and finish with some level of nitrates... let's say 10 ppm. You now let your tank go 4 weeks without adding anything to create ammonia, and you don't do any water changes. Your water parameters now should be the same as when you left it, 4 weeks ago - 0 ammonia/nitrite and 10 nitrate. That doesn't mean you have any bacteria left though.

[roka64]

Hmmm, that's an interesting point. I have a tank that has been running for a few months (was going to be a QT, just haven't had any new fish come in lately), so I will test that water parameters tonight. Now that I think about it, you probably are correct since that tank has algae growing in it....