I like to keep minnows in a spring hole at the cabin.They last a long time in the ice cold clear water and the water running into the sump hole keeps it oxygenated.
Dont take them out of warm water though and drop them directly into the cold spring-it will kill them from shock.

Great info guys. Appreciate all replies!

1 *c per hour change faster up or down is shock effect

I had a guy near here that used sunken 55 gallon plastic barrels with holes drilled in them (lots and lots of small holes like 1/4"). Said it was easier of the fish. He kept goldfish for flathead bait in his.

If you had a place for it you could keep them in an aerated big round horse water tank. I use a smaller one for bullheads. I have a deep freeze near it and in the hot months I swap cat litter buckets of water in and out to keep it cool.

A bait shop I used to go to had a working deep freeze they used for live bait. It had an aerator and was kept running with the lid open. The water stayed cool and the bait fish were very lively.

the guy that I knew jut dugout the upstream side of a swamp creek and put screen over the culvert. just a small stream back in the woods, he actually had his son and I dig it.

he just got fish food at local feed mill, he kept them in there for years, I always wonder why the coon didn't eat them all.