I buy minnows from a local bait store, frequently feed them to my eastern painted, and occasionally to my red-eared slider. I always put them in the refrigerator. Sometimes they all survivee for weeks, and sometimes many die shortly after getting them. Could the difference in mortality be from different amounts of food the eat? I don't know what they eat. When I had goldfish feeders, I fed them goldfish food - but I don't know whether minnows would eat that stuff.