Well, with budget concerns in mind, I'll say pellets or flakes can make up a good portion of a healthy diet...like 2/3 or so. Giving them the krill a couple or three days a week is not bad, but if you switch foods for those 2-3 days, say 1 day frozen brine shrimp, 1 day krill and 1 day wax worms that will give them a good variety of food. It is more cash up front to go get 2 more kinds of supplemental food, but you will not go through them as fast by switching them around. Also, rehydrating the freeze dried krill in some tank water for a few minutes before you drop it in the tank will help lessen the likelihood of tummy troubles and they might eat less of it because the moisture will help them feel fuller.