With the never-ending choices of fish foods available to the aquarist today, it may seem difficult to determine which are appropriate for your fish. The cost factor should NOT be the deciding factor when choosing fish food, because inferior or inappropriate foods do not save money in the long, run when the health of the fish is jeopardised.
Most popular species of aquarium fish will eat flake foods. Flakes soften quickly without disintegrating in the water and do not sink to the bottom too rapidly. When they do finally pass through the water over a period of time (if not gobbled all up immediately) they are progressively fed upon by top-feeding, middle-feeding, and bottom-feeding species of fish. Unless your fish are top feeders only, a diet solely of floating flake is no recommended. A lot of air is swallowed by the fish as the gulp down the flake, and often it is eaten before it absorbs any water, making constipation a problem. If using flake in the main, try giving your fish no feed 1 day a week, and mashed, frozen green peas(remove the outside shell) 1 day a week.
Granules, bits or small pellets have the disadvantage of sinking too quickly and becoming lost in gravel bottoms. This excess food will spoil unless cleaned up by catfish, loaches, or other scavengers. Sinking foods are a good choice for bottom-feeding fish, because the pellets are relatively dense and permit large size fish to eat their fill more easily, than with flakes.
Floating pellets are good for cichlids, goldfish, catfish, and other large fish that feed at the water surface. They are especially good for garden pools or ponds, because the fish can be watched as they surface to eat, reducing the likelihood of overfeeding. Floating pellets do not disintegrate as quickly as most sinking pellets do.
Selecting Live Food
Plankton: Despite advances in fish nutrition, there remains a need for fresh foods, including live organisms. Plankton can be netted or trapped from ponds for feeding fish in tanks. These are minute floating aquatic plants and animals.
Mosquito larvae: Accessible to most fish owners and eaten by most fish. Want to find out if you can harvest mosquito larvae in your area. You outside at sunset. If you get bitten by mosquitoes, then you can harvest mosquito larvae. Place a bucket in a shaded place with a few lettuce leaves in it. Forget about it for a week or so. Check it, its likely have mosquito larvae in it. Filter them out and drop them in your fish tank. Your fish will love you.
Tubifex worms: are a live food that are known to carry fish diseases. The risk is greater for live foods caught in the wild than for those reared in captivity. Rinsing live food with water can help to limit disease introductions into the aquarium, but cannot be expected to remove internal parasites from an organism.
Microworms: These are one of the simplest live foods to culture for larval fish. They are suitable for a first or second food for fish too small to feed on brine shrimp.
Brine shrimp: (Artemia salina) Are minute crustaceans collected from saltwater ponds around the world. Their unique cysts remain viable even when dried, so they can be stored on the shelf to be hatched months later when needed. One gram of brine shrimp contains about 250,000 cysts. Each cyst containing one single animal, but not all will hatch. Different strains of artemia vary in size and and nutrient content.
Earthworms and white worms: Common red earthworms can be cultured as food for larger fish. The white worm in another popular food, about 1cm long. It is often found in association with red earthworms and can be reared under similar conditions in a separate bed.
There are so many other live foods available for the aquarist today. You can visit your local hatchery or pet shop to find out the many foods available in your area.