I'm keeping one Tadpole Madtom with a half dozen Longear Sunfish in my 125G. The sunfish are pretty aggressive, but they stay out of his way. I keep them at room temperature (68F) with lots of hiding places for the madtom. He likes dark, confined spaces that he can dart out of to grab food. I have to target feed him pellets with some tongs since the sunfish never let anything hit the sand.