Originally Posted by SaraB
Not if they have adequate swimming room and are healthy. They should be swimming around the bottom and around not sitting in one spot.
Mine only swim around when food is present or they think food is about to be present/I'm in the room. Otherwise they find a shady spot and chill. They're all pretty healthy.
Op- are we talking peppered cory? Nano species? How big are the ones you have currently?