1, keep the water level in the pond stable.
In the cold winter, properly raising the water level and increasing the water capacity can not only maintain a relatively stable water temperature, but also improve the water quality conditions. The water level of the fish pond should be kept at about 2 meters. When the water level drops 10 ~ 15cm, fresh water must be replenished to keep the water level and water quality stable.
2. Adjust the water quality regularly.
Ponds with water sources should be filled with fresh water once every 10 ~ 15 days, with 20 ~ 30cm fresh water each time, and the old water should be properly discharged; Sprinkle lime slurry every 15 ~ 20 days to improve the calcium concentration in water; Apply phosphate fertilizer again in about 20 days to improve the phosphorus concentration in water and enhance the cold resistance of fish; Ponds equipped with aerators are opened from noon 12 to 2 pm on sunny days to promote the circulation of surface water and bottom water, make dissolved oxygen uniform and reasonable, and increase the appetite and disease resistance of fish. When the weather is bad (sultry, rainy, etc.). ), the aerator should be added at night, usually from midnight to dawn.
3. Timely repair damaged fishery facilities such as heat preservation sheds, and strive to reduce the loss of overwintering breeding objects; Do a good job in freezing prevention of fishery production facilities. In rainy days, the film on the windward side should be thickened and the base column of the greenhouse should be lengthened.
4, appropriately reduce the density of fish culture, to prevent the phenomenon of hypoxia death due to the high density of fish.
5. Reasonable feeding can improve disease resistance.
In cold winter, feeding concentrated feed properly can supplement the energy of fish life activities and improve the survival rate. When the water temperature is above 5℃, it is usually fed once every 3 ~ 5 days, and the daily feeding amount is 0.5% ~1.0% of the fish weight; When the water temperature rises above 8℃ in sunny days, the activity of fish increases, so the feeding amount should be increased appropriately.
6, try to reduce the operation
In addition to ensuring the special requirements of market supply, minimize production operations. Fishing operations should be suspended during severe cold, and fishing ponds and parent ponds should be avoided as far as possible to avoid fish damage.
7. Strengthen disease prevention and control.
In the cold winter, due to the low water temperature, fish's immunity decreases and their disease resistance is weak, so they are easily infected and attacked by fungi (Myxosporidia) and parasites (Myxosporidia, Trichinella, Gourd Trichomoniasis, Third Generation Trichomoniasis and Anchovies). Strict disease prevention measures should be taken and water bodies should be disinfected regularly.
Second, increase dissolved oxygen.
Each pond is equipped with 1 impeller aerator, and the power is 1.5kW, so as to ensure the low dissolved oxygen content in the pond water and start the aerator when the fish slightly floats.
Thirdly, the adaptation of tilapia to the environment
The suitable water temperature range for tilapia is 18℃ ~ 38℃, and the optimum water temperature is 28℃ ~ 32℃. Resistant to low dissolved oxygen, can still eat in water with dissolved oxygen content below 0.7mg/L, and can still survive and reproduce when the dissolved oxygen content in water is 1.6mg/L; Can be in 17%. It can grow, develop and reproduce in seawater below salinity, and can grow in water with pH 4.5 ~ 10.