Key points for autumn adult fish farming management

Regulating water quality. In autumn, the water temperature is suitable, making it the peak growing season for fish. Pond fish have strong metabolism and produce a lot of waste, so water quality management should be strengthened to improve the ecological environment. First, keep the pond water relatively deep to expand the water body's fish-carrying capacity, reduce the impact of the water temperature drop after autumn, and extend feeding time. Second, frequently add fresh water. Generally, add water three to four times a month, with each addition raising the water depth by 15 cm to 25 cm. Third, promptly spread quicklime. Do this once every half month, using 15 kg to 20 kg of quicklime per 667 sq m of water surface, dissolve it in water and spread it over the whole pond. This not only disinfects and sterilizes but also increases calcium.

Applying additional fertilizer. In ponds mainly raising filter-feeding fish, when the temperature is relatively high in early autumn, additional fertilizer should be applied in small amounts and more frequently, mainly chemical fertilizer, to avoid water quality deterioration and maintain good water quality that is both fertile and refreshing. After the water temperature drops in late autumn, organic fertilizer should be applied mainly to accelerate the pond water becoming fertile and dense, promote the massive reproduction of biological feed, and provide sufficient nutritional reserves for fish to overwinter. Autumn fertilization should be reasonably controlled according to the temperature, water quality fertility, and fish growth conditions. Generally, apply additional fertilizer once every 15 to 20 days, using 3 kg of urea and 6 kg of superphosphate per 667 sq m of water surface, or 150 kg to 200 kg of decomposed livestock and poultry manure. Keep the pond water oily green or tea green, with transparency of about 30 cm.

Strengthening bait feeding. In autumn, the temperature begins to drop, and the temperature difference between day and night is large. To fatten the fish, it is necessary to ensure a comprehensive, sufficient, and palatable feed supply. In ponds mainly raising herbivorous or bottom-feeding fish, fresh, tender green, pollution-free green feed should be fed first, and after it is eaten, compound feed or other concentrated feed should be fed, once each morning and afternoon. The amount of green feed fed should be suitable for the fish to finish within 2 hours, and the amount of compound feed and other feed should be 3% to 6% of the body weight of the feeding fish. After October, the temperature gradually decreases, and the bait should mainly be compound feed with higher crude protein content, generally fed once a day, with the feeding amount being 1% to 3% of the fish body weight.

Preventing fish from floating to the surface. Entering autumn, in ponds with relatively high stocking density, because of large amounts of bait and fertilizer, there is a lot of organic matter, and oxygen deficiency can easily cause fish to float to the surface. Therefore, pond patrols must be strengthened in the morning, evening, and especially at night. Once fish are found to suddenly reduce feeding or take longer to feed, especially if grass carp only carry grass and swim around the pond without any sign of eating, it indicates that oxygen deficiency has begun in the water. If splashes can be seen on the water surface during the day, and obvious waves can be seen on the water surface after the fish school is startled, it indicates that hidden floating has already appeared. When signs of fish floating are found, change the water in time and turn on the aerator to increase oxygen.

Timely harvesting. After autumn, some fish have reached market size. If they continue to be raised, they eat a lot and grow slowly, so they should be caught and sold in time to reduce pond fish density and allow fish that have not reached market size to grow faster.

Preventing and treating fish diseases. Autumn is a season with frequent fish diseases, and gill rot disease and enteritis disease are very likely to occur, so prevention and treatment of fish diseases need to be strengthened. Baskets can be hung at the feeding area, each containing 100 g of bleaching powder and 150 g of crystal trichlorfon, continuously hung for 5 to 7 days. At the same time, medicated bait should be fed. For every 100 kg of feeding fish, use 1 g to 2 g of oxytetracycline or 2 g of allicin or 500 g of chopped Chinese chives mixed with bait and fed once a day for 3 to 6 consecutive days. In addition, it is strictly prohibited to feed moldy and spoiled feed, and care should be taken to promptly remove residual bait, dirt, and other debris to keep the pond water clean and hygienic.