Originally Posted by PaperclipGirl
Another curiosity question:
Can cynobacteria cause a tank to read low to zero nitrates/nitrites? The reason I ask is when I got this 55g tank it had a lot of cynobacteria (on the light lids), and has never read any nitrates/nitrites ever...
We need a bit of clarification I think. Cyanobacteria is a green slimy film that will cover anything under water like plants, wood, decor, even the gravel. It will easily come off with your fingers.
I can't see how this could be on the light lids; green "stuff" there would likely be algae dried.
With respect to the nitrates, I would expect nitrate to be higher (though not always) with cyanobacteria which is organic in origin, by which I mean its chief cause is high organics, and that usually means nitrates are high. Light is also part of the factor, but the organics are the main cause of cyanobacteria, which as the name suggests is actually a form of bacteria and not true algae.
Nitrite is yet another different thing with no direct relation to cyanobacteria that I am aware of; I have had bouts of cyanobacteria in established tanks with zero nitrite, and nitrates not above 10-20 ppm which is not "high."