Obtain these supplements from safe sources. Insects, worms, and other animal food is most safely obtained at a pet store or aquarium store, while plant matter should be organically grown away from roadside exhaust. If a local aquarium expert tells you that collecting animals or plants from outdoors is safe in your area, then you may follow her advice. Otherwise, understand that collecting these supplements yourself carries the risk of disease, parasites, or harmful chemicals.
Feed carnivorous fish live or frozen animals. One to three times a week, give your fish frozen or live insects and other animal foods instead of their usual feeding. Alwaysresearch your fish species' needs or ask an expert before selecting a food, as some foods can transmit disease or cause digestive issues when fed to certain species. Common foods available at pet shops include bloodworms, tubifex worms, daphnia, and brine shrimp. As with any feeding, only provide tiny amounts of food; enough to eat within 30 seconds may be enough for some species.
Warning:Freeze-dried foods are another option, but should only be used occasionally due to the digestive issues large amounts can cause in some species, such as bettas.
Avoid live tubifex worms, even ones sold at pet stores and raised on fish farms. They are known to cause diseases in many species, although the frozen variety is typically safe.
Feed most fish vegetables or algae.Herbivores and omnivores will likely be healthier and more colorful if you supplement their diet with the occasional plant matter, and even many carnivorous species can eat plants for useful nutrients. As always, research your fish species online before feeding it a new food. You can attach a piece of vegetable inside the tank with a vegetable clip, or cut it into small pieces to feed to your fish. Be sure to remove any uneaten vegetables within 48 hours, or it will start to rot in your tank.
Carrots, zucchini, cucumbers, carrots, lettuce, and peas are just a few of the vegetables your fish might enjoy. Feed once every few days or as advised for your species.
Using spirulina powder, infusoria, algae, or other plant matter sold at aquarium shops is another option, and a necessary one for tiny, juvenile fish too small to eat vegetable pieces. As long as the tank's surface or walls doesn't become overgrown with algae, you may add it according to instructions once or twice a day.
Feed your fish a variety of these supplements for greater health. Different animals or vegetables provide different vitamins, minerals, and other nutrients. Alternate between two or three types of animal or meat (for carnivorous fish) or vegetables (for other fish) for a better chance at providing all the requirements for healthy fish.
Provide straight vitamins or minerals if you notice problems.If your fish's bright colors fade, they become less active, or you notice other signs of poor health, your fish may be lacking certain nutrients. It's best to seek expert advice to gain a better idea of which vitamins or minerals your fish needs, or to identify other problems. Fish may need these supplements during times of stress, such as when new fish are introduced to the tank.
If you are raising live food yourself, or purchasing live food from pet shops, you may feed them mineral or vitamin supplements which then get digested by the predator fish. This technique is called "gut loading."
Seek specific advice for raising newborn fish. Newborn fish, or fish fry, are often too small to eat ordinary fish food. Because their dietary needs are often different than the adult fish, and they may require feeding every few hours, it's vital to seek specific advice based on the species. Research information online to make sure your fish fry have the best chance of survival.