In the past, many fish hobbyists collected, raised, and prepared their own fish food. Today, that is not necessary, as there are many prepared foods available that will adequately meet the nutritional needs of aquarium fish. With the abundance of prepared fish food choices available, you will certainly find one that appeals to your fish as much as (or even more than) live or frozen foods. These prepared foods can be divided into three groups: dry, freeze dried, and frozen.
Flake food, quite possibly the most popular type of fish food, is a form of dry food. Flake food is made by drying ingredients into a very thin sheet, which is then broken up into tiny flakes that can be fed to the fish. Flake food is available in a variety of different formulas, some that are general and can be fed to all different kinds of fishes, some that are made for specific fish types (herbivorous, carnivorous, etc.), and some that are made for specific fishes, such as cichlids, goldfish, or koi. Most formulas include a mixture of flakes that are designed to float, sink slowly, and sink quickly, giving all types of fish an equal chance to get the food they need.
Flake food mixtures are fortified with vitamins and minerals, making them an excellent choice for all small fishes. Any fish larger than about 4 inches will be unlikely to remain healthy on a flake diet, as they will be unable to eat enough flakes to get the nutrients they require. If you have larger fish, you will need to feed them a more substantial diet, but mixing in some flakes now and then will make for a good vitamin-rich treat.
Pellets and sticks are other types of dry food. Available in a variety of sizes, pellets can be of the floating or sinking variety. They are a hard food, so they should only be fed to fish that have mouths big enough to swallow them whole. Because pellets are bite-sized food, they generally produce little waste. Sticks can also be either of the floating or sinking variety. Because of the size of stick food, this type is only suitable for large and very large fish.
Wafer food is comprised of disks which sink to the bottom when dropped into an aquarium. They are available in several different formulations for herbivores and carnivores. Wafers are acceptable food for most fish, but they are best used with bottom-feeding fish.
Freeze-dried foods are made by removing water from organisms under low pressure and low temperature. This method preserves much of the nutrition and palatability that is naturally found in the food, keeping them very close to live foods in terms of their taste, and making them very appealing to most fish. Some common examples of freeze-dried foods are tubifex worms, bloodworms, brine shrimp, plankton, and krill.
Frozen foods were originally used as a substitute for live foods. Today, however, frozen foods are an entity of their own, with many frozen offerings commonly available in the fish trade. Frozen foods are messier than freeze-dried and dried foods because of the moisture retained in them, but higher quality brands of frozen fish food process the organisms so they are less messy. Frozen foods should be kept in the freezer until they are ready to be used. At feeding time, break off a piece (no need to thaw), drop it into the tank, and watch your fish devour this tasty treat.