In the autumn and winter, when the cold wave arrives, the water temperature of the fish pond drops, often accompanied by rainfall, and even occasional frost. In this kind of weather, the water temperature drops fastest and lasts for a long time. The A. tilapia in the pond is most vulnerable to freezing and frostbite. A. tilapia stopped feeding when the water temperature was 15°C, and the water temperature was 8°C as the lethal temperature. The water temperature below 8°C appeared dead fish for 2 consecutive days, causing serious economic losses to the majority of fish farmers. Therefore, before the onset of the cold wave, fish cold-resistance and disaster-resistance measures cannot be ignored. When the water temperature is as low as 20 degrees Celsius, we must take cold-resisting and disaster-relief measures to strengthen the overwintering management of tilapia to cope with the onset of the cold wave and reduce the economic losses caused by the cold wave. at the lowest limit. Below, the author will make a summary of the main technical measures for the prevention and treatment of cold-water fish in the tilapia fish stocks as follows, for reference by the majority of farmers. Management measures before the cold wave Before the cold wave arrives Before the winter starts, you need to grow and fatten the broodstock, fry, and adult fish that need to be overwinter. By feeding the concentrate feed, strengthening the cultivation, increasing the fat storage in the fish, and enhancing the fish's constitution, it can cope with the physical energy consumption during the winter and avoid the fish from overwintering due to factors such as weak constitution and thin body shape. Heighten the water level of the pond and use the geothermal heat generated by the pond to survive the cold winter. In the farms that have neither the conditions to build the wintering shed nor the hot springs and the factory waste heat utilization, the water level in the pond should be as high as possible and generally reach 3.5 meters. ~4 meters is appropriate, the deeper the water level, the larger the water body, the slower the decline of the pond water temperature. In normal years, if there is no cold wave frost, the water temperature of the bottom layer of the pond in the south can be maintained at about 15 DEG C., so that the tilapia etc. Warm-water fish can survive winters safely and naturally. Build wintering sheds and resist cold disasters. Choose a leeward sunny pond with an area of ​​5 to 6 acres, a water depth of 2 to 3 meters or more, and a pool of rainwater that cannot flow in. Construct a "human" shaped scaffold with bamboo or iron supports. Plastic film. In this way, when there is sunlight, sunlight can shine directly on the surface of the pond, increasing the temperature of the water body. However, the film should not be eagerly covered. When the water temperature significantly drops to a low level of 15°C, it will cover the entire film. If the temperature is still high, premature coverage may cause water quality to deteriorate. Ponds should be pre-equipped with aeration and refueling facilities. People in Guangdong and Guangxi Provinces generally do not need artificial heating. Utilizing ground heat, if not particularly cold, they can generally safely pass winter. This method is suitable for wintering of broodstock and fingerlings. Each cuboidal body of water can be stocked with 15 to 20 broodstock, or about 200 to 10 grams to 20 grams of fingerlings. To strengthen management, when the amount of feed is appropriate, the water temperature is higher when the weather is clear. When the tilapia fish activity is more active, the tilapia fishes will continue to grow and may be fed in appropriate amounts. The daily feeding amount is generally about 0.4% of the fish body weight. When the water temperature is low, the fish groups stop feeding, and generally do not feed, so as to avoid waste, and even affect water quality, affecting the overwintering effect of fish. Pay close attention to the weather forecast and take emergency measures in a timely manner. Adhere to the record of water temperature changes and master the dynamics of water temperature changes. When the water temperature is too low, feasible emergency measures must be taken to minimize losses. Response measures during the cold wave Make full use of the factory waste heat and hot spring water to achieve the safety of winter fish overheating (such as waste heat of the power plant), and for the pollution-free water or hot springs, when the cold wave comes, hot water can be directly introduced into the fish pond to make the pond water temperature. Maintain a certain value to ensure the safety of fish. This method works best. During the cold and rainy season in winter, appropriate warm water is added to the pond every day. A. tilapia can not only safely pass winter but also grow normally. This method has a wide range of applications, and is applicable not only to adult fish breeding but also to broodstock or fingerling wintering. It is a wintering and anti-freezing fish wintering method with the lowest cost and best effect. In wintering sheds, prevent cold rain from entering the overwintering pool during cold spells. Avoid the influx of cold rainwater into the overwintering pool. A large amount of cold rainwater will cause the water temperature to decrease. Stir the water layer, affect the stability of the water quality and temperature, and cause fish frostbite and freezing. . Therefore, cold water must be prevented from flowing into the pool. Adjust water quality, ensure that dissolved oxygen is sufficient, including hot spring water, well water, or waste heat of the factory. The pond water temperature can be adjusted by adding warm water to the water. At the same time, the water in the winter shed can pass through the shed. The arranged plastic pipe with many small holes is connected to a blower outside the shed to increase oxygen and regulate water quality. When the outside temperature rises, the ventilation of the shed must be promptly opened. When the water temperature is appropriate, new water should be replaced as appropriate to prevent the fish from lacking oxygen. Cold waves often cause deterioration of water quality in the ponds, resulting in darker water bodies. Most of these conditions are caused by the death of a large number of algae in the water body. Therefore, when this happens, measures should be taken to prevent the death of algae and take practical measures to solve them. When the water temperature is low, avoid stirring the water temperature of the water body for a relatively low period, especially when it is accompanied by rainy days, and avoid fishing or other operations that stir the water body. Keep water stable. In order to avoid fish damage, fish diseases, and even dead fish phenomenon, causing unnecessary losses. If the cold weather is particularly strong and the temperature is extremely low, it is estimated that taking the above measures will not solve the problem of cold protection. If frostbite and frozen fish are unavoidable, decisive measures should be taken to prevent the overwintering operation. Difficulties, reduce fish wintering costs and reduce aquaculture risk. Minimize unnecessary economic losses. Prevention of fish disease during cold winter Ao tilapia generally has fewer fish diseases, but after being injured in winter, it is most vulnerable to watery mildew, which can be immersed in splendid potassium permanganate or spilled, or used 400 ml/l salt and baking soda ( 1:1) solution Quanchiposa, can effectively prevent the occurrence of watery mildew. After the cold has passed, it is necessary to adjust the water quality of the pond to live, tender, cool and fat as soon as possible. At the same time, the water quality is slightly alkaline, ensuring that fish can grow rapidly. Hydrochloric Acid Series,Food-Grade Potassium Chloride,Potassium Chloride,High Purity Potassium Chloride LIANYUNGANGLONGTAIWEI FOOD INGREDIENTS CO.,LTD. , https://www.longtaiweifood.com