I have a 12, 28, and 72 gallon tanks. I’ve been having a lot of problems out of the 12 and just recently the 72 started having issues. I can’t keep fish alive at all in the 12 gallon and the 72 gallon just recently started losing fish like crazy. I bought a nitrate kit because i was told by one fish store that that’s probably the problem. I tested the 72 it was way high, then I tested the 28 and it also showed high but I’ve never had issues with that tank so I took water samples to another fish store. They said all tanks showed normal on nitrates but the nitrites in the 72 and 12 were way off. I’m not sure exactly what they were the fish store just told me not to do anything with those two tanks to leave them alone. I need other opinions on what I should do though because i don’t want to lose more fish.


