I probably took the cover off too soon. I didn't loose any fish the last few weeks when it was cold but it warmed up like spring and I lost 9 fish in the last few days. Honestly since it got warm I thought I was home free from loosing any fish. Why did so many wait till it got warm to die?
SS, without seeing your particular situation, my first good guess for the deaths would be the warmer temps causing a rapid decay and breakdown of fish and food waste which resulted in a rapid ammonia level increase coupled with a low temperature induced supressed immune system in your fish. Your beneficial bacterias as well as harmful bacterias are not as active in cooler temps. The higher water temps allow the bacteria to rapidly grow and reproduce causing harmful bacteria to infect weakened fish, decay rates increase rapidly and your beneficial bacteria and the fish immune systems are always a step behind in growing as they are reactionary to the byproducts of the more hamful bacteria.
