Black carp culture waters should be selected in waters with good ecological environment, sufficient water resources and no or no direct pollution from industrial waste, agriculture, urban life and medical waste.
There are no pollution sources that pose a threat to the aquaculture water environment in the upwind and upstream of the aquaculture water area and irrigation water source.
2. Remove excess sludge from the pond.
Sludge consists of biological corpses, residual bait, feces, all kinds of organic debris, all kinds of organic matter and soil sediments.
Through the decomposition and ion exchange of bacteria, it is continuously dissolved and released into water, providing nutrients for the reproduction of bait organisms.
However, excessive sludge will produce a lot of hydrogen sulfide, methane, organic acids, lower amines and mercaptan, which will accumulate in water and affect the health and growth of herring. Therefore, excess silt should be removed.
The specific measures are to drain the pond water every one or two years and dig out excess sludge, so that it is more appropriate to keep the sludge at the bottom of the pond about 20 cm. At the same time, the bottom of the pool is exposed to the sun and freezes, killing pests, parasites and pathogenic bacteria.
3, pond water disinfection
Improve the pond environment, eliminate pests, prevent some bacterial diseases, and disinfect ponds and water bodies.
The commonly used disinfectants and their dosage are as follows: clean the pond with 200 mg ~250 mg of quicklime per liter, or spray the whole pond with 20 mg ~25 mg of quicklime water per liter; Clean the pond with 20 mg bleaching powder per liter, or spray the whole pond with 0 mg ~ 1, 5 mg bleaching powder water per liter for disinfection; Spraying sodium dichloroisocyanurate solution with concentration of 0. 3mg ~ 0. 6mg/L for disinfection; Or use the trichloroisocyanuric acid solution with the content of 0.2 mg ~ 0.5 mg per liter for the whole pool spray disinfection.
4. Water quality management
Water environment is the basis for herring to live and grow in ponds, and various fish culture measures also act on fish through the environment.
Therefore, water quality management is a bridge for pollution-free herring culture. Ensure that the pool water is rich in plankton, organic matter and nutrients; The transparency of the pool water should be kept between 25cm and 40cm.
The dissolved oxygen in water is above 4 mg, and the pH value is 7 ~ 8,5. The water quality meets the requirements of fat, liveliness, tenderness and freshness.