Thank you for your question. When feeding your discus it is recommended to try a different variety of foods to ensure they are getting the proper nutrition. However, if your fish are only eating a certain kind of foods and spitting out others, you may want to try adding a garlic supplement to the food. These supplements would include Garlic Xtreme, Garlic Guard, or Selcon. By mixing one of these supplements with the flake food or other foods you are trying to feed it will entice them to eat more and also boos their immune systems.