They are by design a genetically weak fish, so anything to reduce stress is key. Keeping pristine water quality is one way, a quality diet is another, and keeping the fish dominant in the tank (to reduce aggression issues from other fish) is another. FYI - when Jeff first brought this fish in many years ago I asked him what he was feeding all of his imported juvies - he fed commercial catfish crumble, and the fish did just fine on that. Not exactly what most would consider a high quality feed. I raised mine on NLS, but Otohime food should be fine too.