Ibc tote system. 4 years old or more channel cats. I added 100 cat fingerlings few months ago. They are dead now and are starting to get to my old fish. I haven't had many problems that I couldn't figure out. Changed the water out twice. All water levels seem to be fine. The fish kinda hang out together and seem to barrel roll when swimming. My friend added 100 from the same company the same day and his are all dead from ick. It sounded like ick but these fish don't have spots or any different colors. I don't know about this one. Maybe I got a bad batch. I haven't lost a fish in a year or more.