Detailed explanation of key technical points for soil-free loach culture in cement ponds

I. Using old cement ponds for culture: disinfection must be carried out first. After the construction of a new cement pond is completed, dealkalization must be carried out. Fill the cement pond with water and soak for 10 days, changing the water once every two days, or use chemicals for dealkalization treatment.

II. Transplanting aquatic plants is the key to soil-free culture. Water hyacinth or alligator weed is selected as the aquatic plant, covering two-thirds of the cement pond area. After disinfection with a 20 ppm potassium permanganate aqueous solution, they are placed in.

III. Use organic fertilizer to cultivate water quality and provide natural feed for loaches. The amount used is 1000 jin per mu. Put it in snake-skin bags and place them separately in the pond.

IV. Before the loach fry enter the pond, soak them in 3-4% salt water for 4—5 minutes to kill pathogens and parasites. The stocking density of loach fry is 80-100 fry per sq m, and the stocking size is 5 cm-8 cm per fish. The water temperature difference when entering the pond should not exceed 3°C-5°C.

V. After the loach fry enter the pond, control feeding for 2—3 days to give them an adaptation process. The feeding amount is 5%-8% of the body weight of the stocked loaches, increasing gradually from less to more. Feeding should be at fixed times, fixed locations and in fixed amounts. Feed once each in the morning, at noon and in the evening every day. After feeding, it is best if the feed is eaten within 2 hours.

VI. Change water in time and disinfect regularly. When the water transparency drops to more than 20 cm, drain and refill the water in time. Disinfect regularly with bleaching powder, etc. Splash EM bacteria once every half month to regulate water quality.

VII. Disease prevention and control. During loach culture, attention should be paid to disease prevention and control. Common diseases include red fin disease, saprolegniasis, gas bubble disease, bent bone disease, trichodiniasis, epistylis disease, pesticide poisoning and other biological enemies, etc.

VIII. Harvest and market in good time, catching the large and leaving the small. Generally, harvesting can begin after National Day. At this time, the loaches have grown to 5—7 times their size at the time of stocking, and the feed-to-meat ratio is the most suitable. It can also be determined according to the local market situation. When harvesting, leave the smaller loaches to be sold the following year.

IX. Do a good job of overwintering and heat preservation. In winter, a certain water level should be maintained in the cement pond. When it freezes, the ice surface should be broken every day to maintain dissolved oxygen in the water. If conditions permit, plastic greenhouses can also be used to ensure that loach fry and loach fingerlings overwinter safely.