Has anyone had success keeping bluegills in a tank? I have a 50 gal aquarium in my garage but have limited success at this, seems they do well for awhile then for no apparent reason will start dying. There's usually about ten to fifteen gills in at a time. I try to keep the water clean and change 20 percent every couple of days, check and control the PH. I fish every three or four days so they aren't in there for extended periods. Any ideas would be appreciated.