Fish food is not optional when setting up an aquarium. Researching in advance whether your aquarium fish will do well with flakes or pellets and having fish food ready before buying your aquarium fish will save a great deal of stress. Frozen fish food is also available and provides high quality nutrients. Nutritional needs of your fish will vary by type, as well as by age. Bottom feeding aquarium fish will prefer sinking food, while fish that swim at mid- or top-level will likely prefer flakes or floating pellets. Choosing the right tropical fish food is critical to the initial success of your fish and their long term health.