Personally, I wouldn't use live feeders, especially minnows because of the risk of introducing disease or parasites. Commercially prepared foods are adequate for healthy fishes, (there are a few exceptions). When the fish get larger perhaps a pellet food, which is more concemtrated than flake. I feed a mix of various flake and pelleted food,as well as live food, such as daphnia, white worms, bloodworms, as well as lettuce and other greens, depending on the type of fish. What type(s) of SA cichlids do you have?