Originally Posted by aqua_chem
You're right so far. In the linked paper, nitrite only got as high at .7 mM though (Figure 6), which converts to 32.2 ppm
We picked up on the nitrobacter taking over at higher nitrites and surprising nitrospira a while back but maybe didn't go in to it in enough detail. Could explain why nitrobacter is the dominant bacteria in waste water plants. Problem is, there's not enough research on nitrospira as I think it's not been long since this bacteria became apparent for nitrification.
So we need to find more on nitrite toxicity or if it's doing any good having to switch from bacter to spira and back again if spira doesn't die. It must come back though or cycles wouldn't complete at all but it definitely could stall. But do we know at what levels this happens?