I am testing my water with the test strips and am getting really high reading's on my nitrites. Is it possible to be getting a false positive reading? Fish are active and eating and seem to be doing just fine. I have now done 3 30% to 50% water changes every other day. The levels of nitrite have not come down at all. Any help would be great. I have a 55g with 12 small fish. A pleco,3 rummy nose tetras, 3 zebras, 2 glass fish and 2 cockatoo cichlids.