Try feeding them a bit of meat as well. While I feed shrimp pellets daily I also give mine shrimp or krill once per week too. Just have to chop it up to bite size pieces for them while they are still small guys. I usually give them about 3-4 small chopped up pieces each. Well, I try to give it to each, but one of them is a food hog and grabs more than his share lol