Only fish I have had a problem keeping alive is crappie. I think I need to immediately get the fish to a tank, instead of continuing to fish for another hour or so. I even add and drain the water every 45 mins to an 1 hour with double and triple airstones while I am at the lake. I change and drain water before I head to the house. The crappie lays on it's side before I get it to the house. I have no problems with perch, sunfish and catfish.