Homemade Dried Foods.
The oldest dry food known to aquarists is dried Daphnia. To this day, in almost all “bird” markets of the country, you can meet suspicious-looking old women selling this, if I may say so, “food” from bags, by weight and by glasses. Unfortunately, nothing good can be said about this food. Natural Daphnia is indeed a very nutritious and valuable food, but in order for at least part of the nutrients contained in this crustacean to be preserved during drying, it is necessary to use special, rather labor-intensive drying technologies.
Naturally, market craftsmen do not follow any technologies, and as a result, their bags contain not food, but dried chitinous shells with traces of oxidized, degraded proteins and fats, which not only have no nutritional value, but are simply frankly harmful and dangerous to fish. Moreover, dried Daphnia, Cyclops, Gammarus, and bloodworms without compliance with technological standards are a fairly strong allergen for humans. You should not use these homemade foods if you do not want to ruin the biological balance in the aquarium, and they do not contain the necessary nutritional elements for fish!
But if there is no other food in your region, then dry Daphnia and Cyclops should be strongly crushed with your fingers to a dust state during feeding, because small particles get wet faster and are easily digested by fish, while large ones, without having time to get wet and swallowed by fish, begin to swell in the intestines, which causes inflammation. You can pour hot water over crushed Daphnia for 10 minutes, and then rinse it in a net. To improve the palatability of dry Daphnia, it should be sprinkled with sunflower, hemp, linseed, or other oil. To increase nutritional value, 1/4 of dry Gammarus is added to Daphnia. Dry Cyclops should be used very carefully, because it quickly decomposes in water and becomes covered with fungus. Dry Daphnia and Cyclops are stored in a glass jar covered with gauze in the refrigerator. A large amount of dry food can be stored longer if it is frozen.
For feeding various adult fish, the following mixture is used: 2 cups of Daphnia, a cup of Gammarus, a quarter cup of milk formula, a quarter cup of crushed hemp leaves and a quarter cup of crushed lettuce leaves, a cup of finely chopped bloodworms or Tubifex. The mixture is thoroughly stirred, ground in a mortar, and dried in the sun or in the oven, placing it on a sheet in a 1 cm layer. The dry mixture is ground into a powder once again, which is stored for a long time on the bottom shelf in the refrigerator. Before feeding, small balls are made by moistening the mixture with water.
Other Foods for Aquarium Fish.
The composition of food for such aquarium fish as large cichlids, catfish, piranhas includes lean beef, beef liver, fresh or frozen fish fillet. These products are cut into small slices corresponding to the size of the fish, washed well with cold water from blood, and fed. Small species of carnivorous fish can be given scraped meat also after washing it with water. Salted and canned meat should not be given to fish.
Feeder fish. If you keep predatory fish, they eat only live food. Do not use guppies and other “feeder fish”, which may contain parasites and serve as a source of disease. It is preferable to use earthworms, bloodworms, and other foods that pose a lesser risk of disease spread. Feeder goldfish are used to feed large predatory fish – piranhas, catfish. These unfortunate creatures are usually kept in a store in a tank with a stocking density about the same as that of sprats.
Often, due to maintenance conditions (they are not fed to reduce the amount of dirt in the water), fish are full of parasites that can be transmitted to your half-meter pet. The presence of vitamins and everything else in these fish is highly questionable. In principle, large predators can be accustomed to substitutes, such as meat. Many other fish – all those capable of swallowing them – cichlids, etc., will not refuse small guppy fry. If your friends have guppies, which usually spend all their free time breeding, the unnecessary fry will diversify your fish’s menu.
Frozen seafood and marine fish. In aquarium practice, frozen seafood (squid, shrimp, mussels) and marine fish fillets (cod, pollock) purchased in regular grocery stores are widely used. Of course, they are not subjected to any chemical treatment before freezing, but this is not scary, because pathogens of freshwater fish diseases are practically not transmitted with marine organisms and marine fish. For this reason, you can safely feed aquarium inhabitants with such foods without fear of introducing an infection.
This is a very good food, rich in protein and other nutrients for many fish species, especially large ones. Seafood and marine fish for small fish are ground in a blender before feeding, and large fish, especially predators, are simply fed pieces of chopped squid, cod, and shrimp. Of course, all seafood must be thawed and thoroughly washed before feeding.
House fly (Musca domestica) is an excellent food for large insectivorous fish, and fruit fly (Drosophylla melanogaster) for small ones. Both adult insects and their larvae are used as food. Drosophila, adults and larvae, can be obtained in specialized scientific laboratories studying genetics. Before feeding, drosophila are anesthetized with ether or cooled. It is more convenient to cultivate the wingless form. The drosophila larva serves as an excellent high-protein supplement in the diet of fry of many fish species. You can also feed fish with horsefly larvae (Tabanus) up to 4.5 cm in size, deer flies (Chrysops), ornate blackflies (Simulum ornatum) up to 8 mm, crane flies (Tipula gigantea) up to 4 cm, drone flies (Eristalis tenax) up to 2 cm, soldier flies (Stratiomyia chamaeleon) 5 cm, and others encountered along the way in catches. Flies diversify the menu of small-sized fish, especially those that in nature feed on insects falling onto the water surface.
Crickets (Achetus domesticus) are commercially bred. They can be kept at home for several weeks. It is necessary to ensure that there is enough food for them (they can start eating each other) and water, without which they will die very quickly. Store-bought crickets are usually sterile and do not reproduce. This is even a plus, since crickets that escape during feeding will not establish themselves in the house. But maintaining a cricket culture at home is, in principle, not difficult, although it only makes sense if you need a lot of them. If you are not allowed to keep crickets in the house, try freezing them. Fish, especially hungry ones, eat such crickets without problems.
In the natural diet of many insectivorous exotic fish (Fundulus), ants make up a large percentage. For feeding purposes, cockroaches (Blatella, Blaberus, Periplaneta, etc.), crickets (Acheta domestica), stick insects (Carausius morosus) are bred on animal and plant media. If necessary, vitamins, trace elements, etc., are injected into insects before feeding.
If you have open decorative ponds in your country house, you can significantly diversify the food base with a simple device. A portable reflector turned on at night is mounted above the pond surface. Thus, solely at the expense of insects attracted to the light, the need of fish (egg-laying toothcarps, cyprinids, etc.) for high-quality food is completely satisfied.
Plant foods. Plant foods can be used as. 
