Bloodworms seem to be the winner, problem is the tetras love em too, I thaw out a cube and keep em in the fridge. I drop a few in 3 times a day. I just gave them some krill and they seemed to like it. Will get daphnia on my next trip. I leave the lights on for a few hours, not long. Have had them for almost a week. The zebras are active but the kuhlis are shy.