Grass carp is the easiest to get sick, so pollution-free grass carp should have a special breeding base, and it should form a certain scale, and there is no pollution source around the base. The aquaculture base has sufficient water, good water quality, smooth water intake and drainage, no communication between fish ponds, convenient fish transportation, rich feed resources and good ecological environment conditions.

2. Selection of fish species

If you want to raise grass carp well, you must choose healthy and lively high-quality fish. Parents of self-propagating and self-rearing fish should come from qualified raw material farms recognized by the state. The fry culture is pollution-free, the quality meets the relevant standards, and the variety is excellent. If the conditions are met, it is best to self-reproduce and self-reproduce. If the fish is imported from other places, it must pass quarantine before it can be introduced.

3. Fish disinfection

Fish must be disinfected before being put in. Chlorine dioxide is 20-40mg/L every 5 5- 10/0min, salt is 5-20min 1%-3%, salt is 8mg/L every15min, and potassium permanganate is 0/5min. The stocking ratio is 80∶20, that is, grass carp accounts for 80% and fish farming accounts for 20%.

Step 4 feed scientifically

Grass carp mainly feed on aquatic plants in natural waters. In pollution-free culture in ponds, it is advisable to use granular feed with scientific proportion to reduce the pollution of residual bait to water quality and fully improve the utilization rate of bait. It should be tender, fresh and delicious, and fed with flood and dry grass. Cakes and other baits should be mouldy, pollution-free and non-toxic. After being crushed, soaked and cooked, they can be made into bait which is easy to eat and digest for grass carp. The principle of timing, positioning, qualitative and quantitative feeding should be adhered to, and the reasonable feeding amount should be determined by observing the weather, water body and fish's food intake.

5. Feed fishery drugs reasonably

Fishery medicine is a substance used to control aquatic animal and plant diseases and insect pests. If used improperly, it is easy to remain in fish, resulting in unqualified fish quality, so it should be used with caution. Fishery drugs generally include bactericides, insecticides and water quality improvers. At present, some traditional fishery drugs, such as chloramphenicol, furazolidone, sodium pentachlorophenol, malachite green, sulfathiazole, tylosin, etc., have been banned and cannot be used in aquaculture. Special attention should be paid to the choice of fishery drugs.