Originally Posted by AbbeysDad
Originally Posted by beaslbob
An initial nitrate value is part of a planted tank cycle as the plants are consuming ammonia for nitrogen.
Just let things be and nitrates will drop down once the aerobic bacteria build up and consume the ammonia.
This statement is incorrect. aerobic nitrosomonas bacteria oxidizes ammonia into nitrites and aerobic nitrosprira bacteria oxidize nitrites into nitrates....as a result, nitrates increase. There are species of anaerobic bacteria that will oxidize nitrates into nitrogen gas. However, these bacteria can only survive in an environment with little/no oxygen which is extremely difficult to create in a fish aquarium.
Well I do tend to (over)simplify things at times.
and your statment is correct.
But when you setup a planted tank there can be existing nitrate sources like from organic substrates, input water and so on. Not just the nitrates generated from the aerobic bacterial action.
In that case the plants will bypass the nitrates and consume the ammonia instead. So nitrates can initially build up.
I hope new hobbiest are not overly concerned by that as in a planted tank that actually is a good sign. Much better to have nitrates then ammonia in either a new tank or a mature tank that suffered some shock and is recovering.
And I have noticed very high nitrate levels in a marine system for months. Like red on the api test kit. Then in 3 weeks they dropped to 0. The tank was balanced out by macro algae which probably was not only consuming ammonia but also growing and expanding while bacteria consuming builds up (consuming ammonia) and finally dropping nitrates down.
Here are parameters I measured on a new 20g leiden I set up. It show the initial nitrate spike I mentioned.
Still just my .02