FAQ: Food for fish

Soaked food usually sinks by itself, and dry cubes can be pressed onto the aquarium glass for the fish to pick at. For bottom fish it helps to put the food in a feeding dish so it does not mix with the substrate.

Krill are small marine crustaceans rich in protein and natural carotenoids that enhance red and orange colours. They are used as a treat for larger fish and as an ingredient in colour-enhancing foods.

For the first days fry often live on their yolk sac, and after that they need very fine food: infusoria, liquid fry food, powder or baby brine shrimp. The food size must match the fry’s tiny mouths.

Guppy fry are born fairly large, so they eat crushed flakes, fry powder or baby brine shrimp straight away. Feed them several times a day in small amounts and change some water often.

Once the fry have grown and can swallow larger pieces, move gradually to micro granules and crushed flakes. The switch usually takes a few weeks, depending on how fast the species grows.

Fry grow unevenly, so some can already swallow larger food while others cannot. Offering several sizes keeps the smaller ones from going hungry and falling behind in growth.

Yes, fine powders and liquid foods break down fast, so water in a fry tank deteriorates more quickly. Give a little at a time, remove leftovers often and change a small part of the water.

Boiled egg yolk mashed in water is sometimes used as a temporary fry food. It pollutes the water very quickly, so if you use it, give only a drop and be sure to remove the leftovers.

Most cichlid fry can eat baby brine shrimp and fry powder right away, and small granules once they have grown a little. Some species’ parents guard the fry, so feed carefully so as not to disturb them.

In a densely planted tank fry find micro-organisms on plants and moss, so they survive better among them. Still, this food alone is usually not enough, so fry food is needed as well.

Growth depends on the species, temperature, water quality and food. Frequent small feeds, live baby brine shrimp and clean water help fry grow evenly the most.

Baby shrimp eat the same as adults, just finer: biofilm, debris and powdered shrimp food. Moss and leaves in the tank give them both food and shelter.

In summer, when the water is warm, a higher-protein food for growth and colour suits the fish. In spring and autumn a more easily digestible food is chosen, because the fish digest more slowly in cool water.

Feeding starts once the water is consistently around 8–10 °C. At first give very little easily digestible food every few days, and increase the portions only as the water warms.

When the water cools below about 8–10 °C, feeding is usually reduced and then stopped. Undigested food harms fish in cold water, and rotting food pollutes the pond before winter.

It is an easily digestible, lower-protein food for cooler water in spring and autumn. It puts less strain on the fish’s digestion when their metabolism is slower.

Give as much as the fish eat in 3–5 minutes and skim off leftovers with a net. In a well-planted pond the fish find some food themselves, so they do not need much feeding.

In warm weather pond fish are usually fed 1–3 times a day in small portions. During heatwaves, when the water holds less oxygen, it is worth reducing the portions.

When the water is cold and the fish are resting in the deep part of the pond, they are usually not fed. Their digestion has almost stopped, and uneaten food rots and spoils the water under the ice.

Choose the food size by the fish’s size: small pellets for young koi and larger ones for adults. If small and large fish share the pond, two sizes can be mixed.