I fish Okeechobee every year with shiners. If you keep the live well aerated and cool, shiners can live in the square live well for more than 72 hours.
Also of note, for shiners specifically, the live well pump is too harsh for them. It knocks their scales off and injures them before they even go on the hook. This is crucial because bass want to eat something that looks live. Use a live well bubbler instead. If you need direction in finding one, Let me know. I got two for my dad for Christmas last year and they worked great in February for us.