There are ways to rejuvenate weak fish species in autumn.

Due to the hot summer climate, aging water quality and breeding management, many farmers have weak constitutions. These weak fish species, if not rejuvenated in time when autumn is crisp, it is not conducive to the winter of the species, but also greatly affect the yield of the coming year. Therefore, it is very important to do a good job of autumn rejuvenation of weak fish species. The methods of autumn rejuvenation of weak fish species are described as follows:

Zhuanchi, Qingtang

After the spring and summer high temperature season, the general water quality aging, natural organisms reduced, harmful bacteria increased, extremely unfavorable to the growth of fish. After autumn, fish species should be transferred to new ponds for cultivation and rejuvenation in time. If the water source and fish pond turnover is difficult, all the old pond fish can be transferred out of temporary cultivation, more than half of the old water in the original pond can be replaced, and the supernatant of 20-30 kg of quicklime can be sprinkled on the water surface of each mu for disinfection, and new water can be added after 7 days, and then the fish species can be transferred back.

Separate culture, dilute release

Fish species are segregated according to different specifications. Generally, fish species with a body length of more than 15 cm can be put into the main adult fish pond for breeding, and smaller fish species can be put into the special pond for cultivation, so as to ensure that the specifications of fish species stocked in the same pond are consistent as far as possible. At the same time, it is necessary to reduce the density of fish species and reasonably match fish species. Generally, ponds with a depth of 1.5 meters can put 5000 fish species within 10 cm per mu, and can generally grow to about 15 cm by the end of the year. The fish pond mainly raising silver carp and bighead carp can be matched with 30% grass carp; the fish pond mainly raising grass carp can be matched with 30% silver carp and bighead carp. Among them, the ratio of silver carp to bighead carp is 5:1.

feed, fertilize

From the middle of September, it is necessary to increase the amount of bait and fertilizer to ensure adequate nutritional needs. The pond where the grass carp species are mainly raised and matched with silver carp and bighead carp species generally feeds 80 kg of fresh grass per ten thousand fish every day, and supplements about 2 kg of concentrated materials such as bean cake, corn flour and bran. It must be paid attention to feeding green materials first and then concentrated materials to avoid competition between grass carp and other fish. In addition to properly increasing the feed amount of concentrate, organic fertilizer should be added in time to the ponds where silver carp and bighead carp are mainly cultivated. Fertilization is best carried out in sunny days, and the amount of fertilizer depends on the water quality, and it is appropriate to use less and more. Organic fertilizer is generally applied once every other week, and 50-60 kg of decomposed human and livestock manure is applied every mu. Chemical fertilizer is applied once every 2-3 days, 3-5 kg each time, and the application ratio is N: P: K =1:1: 0.5. After the chemical fertilizer is dissolved in water, the whole pond is splashed.

To patrol the pond and prevent disease, we must first ensure that the fish species do not get sick. However, the autumn water temperature environment is suitable for the reproduction of various pathogenic microorganisms, easy to break out fish diseases, large-scale fish species are especially prone to bleeding, enteritis, mumps and other diseases. To prevent the occurrence of fish disease in autumn, first, we should patrol the pond frequently, especially after sultry weather and rainstorm, and pay more attention to preventing fish from floating and flooding. At the same time, observe the feeding and activity of fish; second, insist on timely fishing out residual bait, and sprinkle bleaching powdered water once every 2 weeks on the feeding ground and fish feeding tools; third, improve the water quality, drain part of the old water in the pond every 10-15 days, inject about 15 cm of new water, or sprinkle quicklime disinfection in the whole pond every 20 days or so.