Six ways to prevent crab disease in winter

One is to freeze the bottom of the pool. After cleaning the crab pond, clear the ditch, pump water regularly with machinery, and try to make the bottom of the pond go through freezing and sunlight for about a month, so as to improve the soil condition of the bottom of the pond, so that some pathogens can be killed by freezing and sunlight, and create a good ecological environment for the growth of crabs in the future.

The second is to remove the silt from the bottom of the pool. The main components of silt are large amounts of residual bait, organic matter, dead organisms and biological excreta. Too much silt can easily lead to the deterioration of water quality, but also produce a large number of organic acids, hydrogen sulfide, ammonia and so on, which reduce the attachment value of pond water, inhibit and harm the growth and survival of river crabs, especially harmful bacteria, parasites and other pathogenic microorganisms exist in the sludge. Once the conditions are right, all kinds of pathogens are rampant.

The third is to carry out drug disinfection. 20 days before stocking, crab seedlings should be strictly disinfected with quicklime and bleach powder, 75 kg ~ 100 kg per mu of quicklime, 15 kg ~ 20 kg of bleach per mu and 15 kg ~ 20 kg per mu of quicklime water.

The fourth is to build a good drainage system. In addition to considering sufficient water flow, the physical and chemical factors of the water are in line with the growth of crabs, free from pollution and pathogens, but also pay attention to the mutual infection and repeated infection caused by the same canal for drainage, so it is required that each crab pond can discharge the water separately.

The fifth is to transplant aquatic plants. Aquatic plants can not only provide habitat and molting environment for river crabs, but also provide fresh and delicious plant feed, reduce the content of ammonia nitrogen in water, increase oxygen and improve water quality. Among the aquatic species, submerged plants are bitter grass, small grass, etc., and phytoplankton are water peanuts, duckweed, and so on. These plants have to be sown, transplanted or transplanted in winter and spring, making the crab pond coverage of more than 60%.

Sixth, do a good job of crab body disinfection. Disinfect the crab seedlings with appropriate medicine before going into the pond. It is commonly used to soak in 15 mg ~ 20 mg potassium permanganate per liter for 20 ~ 30 minutes, or with 10 mg bleach solution per liter for 10 ~ 15 minutes.