This has been a real bad *$#%ing day - warning pics are not good natured

[Chin_Lee]

Crappy - the emperor just bit the dust....... queen is still hanging on huffing and puffing away......... RIP

[Der_Iron_Chef]

Originally Posted by Chin_Lee

Crappy - the emperor just bit the dust....... queen is still hanging on huffing and puffing away......... RIP

My initial thought was along the lines of what Tony's thinking. I know you've probably already done this, but are you aerating the %@#$ out of the water? It seems the fish most susceptible to low oxygen levels have died first.