Be careful that the tank you steal the bio from doesn't spike. Even if you think it's just a small percentage of the total it may cause problems if you aren't careful.
For sure, im a little obbsesed about testing! I feel like a mad scientist w/ my api MT! Lol
Op: if you got nitrates then the bb that turns nitrites into nitrates is there! At some point you had nitrites, which may have been low enough to overlook!
GL and before you add fish do a wc!
#1 S. Vettel