That may be your problem and dotty backs seem to really love to hate basslets as well. Not enough hiding spots and the dotty back may be putting a lot of stress on the grammaYou are correct, I never had more than one at a time. The last one spent a lot of time in a hole he dug in the sand under a rock. I don't have a lot of hiding spaces in my tank though as the rockwork is pretty open. Temperature has been constant at 78 degrees for a long time. Would lower be better?