FAQ: Food for fish

In the wild fish are always searching for food, so they act hungry even when full. Swimming at the glass is not a sign that they need more – it is better to stick to a portion they finish in a few minutes.

Healthy adult fish can usually go a few days or even a week without food, and larger ones longer. Fry and young fish cope with fasting much worse, so they need frequent feeding.

Many fishkeepers skip feeding one day a week to rest the fish’s digestion and keep the water cleaner. This does not harm healthy adult fish, but it should not be done with fry and young fish.

First give food to the fast fish at one end of the tank, then to the shy or slow ones at the other end. Hiding places also help, as shy fish come out to feed more confidently from them.

In warmer water fish have a faster metabolism and eat more, so slightly larger portions may be fine. But warm water holds less oxygen, so overfeeding becomes even more dangerous.

Do not shake food straight from the container, as it is easy to overdose and moisture gets into the pack. It is easier to take a pinch with your fingers or a small spoon, and pack dispensers or automatic feeders help give even portions.

It is not essential, but fish quickly get used to a routine and expect food. A steady schedule makes it easier to check that all the fish are eating and to notice changes in appetite.

Goldfish do well on a goldfish food with more plant ingredients and less protein than tropical fish food. It is worth supplementing with vegetables such as blanched peas or lettuce and occasionally with frozen food.

When grabbing floating food, round-bodied goldfish swallow air, which can contribute to swim bladder problems. Sinking granules or pre-soaked food reduce this risk.

Bettas are carnivores, so small high-protein pellets suit them, supplemented with frozen or live bloodworms, brine shrimp or daphnia. Give a few pellets once or twice a day, as bettas tend to overeat.

Livebearers do well on small flakes or micro granules with plant ingredients such as spirulina. Mollies especially like plant food and algae, and occasional frozen food helps keep colours bright.

Small tetras do well on small granules or crushed flakes that sink slowly through mid-water, where they feed. It is worth adding frozen brine shrimp, daphnia or cyclops, as they like small animal food.

Corydoras and other bottom-dwelling catfish need sinking tablets or granules, as they rarely feed at the surface. They are not just cleaners, so leftovers from other fish are not enough for them.

These catfish mostly eat plant food and algae, so algae wafers and vegetables such as courgette or cucumber suit them. Some pleco species are omnivores or more carnivorous, so check your fish’s species.

Cichlid diets vary widely: Malawi mbuna mostly eat plant food, while many American cichlids are omnivores or predators. Choose food made for your group of cichlids, as too much protein can cause digestive problems in herbivorous species.

Angelfish do well on flakes or granules supplemented with frozen brine shrimp, bloodworms or mysis. They feed mid-water, so slowly sinking food suits them.

Discus need varied, high-protein food: special granules, frozen bloodworms, brine shrimp or discus mixes. They are often fed several times a day in small portions, and in warm water leftovers must be removed quickly.

Gouramis are omnivores, so flakes or small floating granules suit them, supplemented with frozen food and plant ingredients. They often take food from the water surface.

Zebra danios and rasboras swim fast in the upper water layer, so small flakes or floating micro granules suit them. They also like frozen daphnia or brine shrimp, worth giving a few times a week.

Shrimp eat algae and organic debris, but they benefit from special shrimp food or blanched vegetables too. Give very little and remove leftovers after a few hours, as shrimp tanks are usually small.