When it comes to feeding your Red Tail Shark, you want to make sure that their diet consists of a variety of foods. A good diet for these fish includes live and frozen foods such as bloodworms, brine shrimp, blackworms, tubifex worms, etc., as well as some prepared sinking pellets or flakes. Be sure to only feed them what they can eat in 2 minutes or less; any uneaten food should be removed from the tank with a net so it doesn't contaminate the water. You may also need to supplement their diets with some vegetable matter such as zucchini slices and blanched spinach leaves. Variety is key when it comes to keeping your shark healthy! Additionally, you should always remember not to overfeed since this can lead to malnutrition and poor health. Lastly, if possible try adding different types of fresh seafood like mussels or squid occasionally into the mix-up too!