I came home on Friday to 6 dead fish. Tested water, textbook perfect. PH at 7.2, no nitrates, no ammonia, etc. I haven't lost a fish (other than eating another) in 4 years. Some fish started to show signs of an ICH like substance, but not all fish and this was not detected when I went to bed the night before. Did a partial water change, stress coat and MelaFix. Lost 8 more on Saturday, 5 more on Sunday. Lost my 8" tinfoil barb I have had for 4 years. The only thing that I can think of is the 3 petco fish that I had purchased a week prior. One survived. What could this be? I have lost 21 fish and have 5 left. If i lose them all, it will stink. How do I clean the tank so when I populate it again I won't have the same problem? I don't want to lose the biological filter if I don't have to. Does this mean that I have to replace the wheels in my penguin too?
Any ideas?
Any ideas?