FAQ: Food for fish

Remove the food from the surface and bottom with a net or gravel vacuum as quickly as possible, before it breaks down. Test ammonia and nitrite the next day and change some water if needed.

Many herbivorous and omnivorous fish eat blanched peas, courgette, cucumber, spinach or lettuce leaves. Wash vegetables well to remove pesticides and take out leftovers after a few hours.

Briefly boil frozen peas or pour hot water over them, remove the skins and mash them into small pieces. They are easy to digest and contain fibre, so they are often given to goldfish as a supplement.

A slice of courgette or cucumber can be weighed down with a clean stone, a stainless steel fork or a vegetable clip with a suction cup. Blanched vegetables sink and soften faster.

Most human food, especially bread, cheese and fatty or seasoned products, must not be given to fish. The exception is unsalted, washed and prepared vegetables for herbivores; otherwise fish food is the better choice.

You can make a gel food from seafood, fish and vegetables blended with gelatine or agar and frozen in portions. Such food needs to be well balanced, so it is best used as a supplement rather than the only food.

Some herbivorous fish, such as certain plecos or large omnivorous tetras, eat pieces of fruit now and then. Fruit is high in sugar and rots quickly, so give very little and remove leftovers promptly.

Mammal meat and mince contain fats that fish digest poorly, so they are not recommended regularly. Pieces of fish, prawns or mussels suit predatory fish better, and food made for them is the simplest option.

Leave a piece of vegetable for a few hours or overnight and remove any leftovers by the next day. A rotting vegetable pollutes and clouds the water.

Floating duckweed is a favourite live plant food for goldfish, some cichlids and pond fish. It can be grown in a separate container and fed by the handful, but in a planted tank it spreads quickly.

Some catfish, especially Panaque and similar species, rasp wood, and its fibre is an important part of their diet. For many other plecos wood is a useful extra source of fibre and a hiding place, but it does not replace food.

In a mixed tank use several types of food: floating flakes for surface fish, slowly sinking granules for mid-water and tablets for the bottom. That way each group gets food in its own layer of water.

Many fishkeepers feed after the water change, once the water settles, or feed less that day. If you feed just before vacuuming, some food gets sucked out and the fish cannot find it in the stirred-up water.

Some fish, such as cichlids or koi, learn to take food from fingers or tongs, which helps tame them. Hands must be clean and free of cream residue, and long tongs are more practical for predatory fish.

A feeding ring is a floating frame that stops flakes from spreading across the surface and into the filter current. The food stays in one place, the fish find it more easily and leftovers are easier to remove.

It is a small glass or plastic dish on the bottom where sinking or frozen food is placed. The food does not mix into the substrate, so it is easier to clean up, and bottom fish and shrimp eat in one spot.

Strong flow quickly carries food into the filter or corners, so the filter can be turned down or off for a few minutes while feeding. Do not forget to switch it back on, which is why a filter pause function or timer is handy.

Treats such as freeze-dried or frozen foods enrich the diet and fish love them, but they should make up only a small part of the total food. They can be given a few times a week in place of a regular feed.

Before spawning, fish are often fed more generously and with more variety, including protein-rich frozen or live food such as bloodworms or brine shrimp. This helps the eggs mature and encourages spawning.

Yes, fish are usually not fed for a day or two before transport so they foul the water in the bag less during the journey. After the move, feed them for the first time only once they have calmed down in their new home.