Prevention of fish hypoxia in winter

In winter, although the intake of fish in the pond decreases, they still need a certain amount of dissolved oxygen to maintain slow breathing. The dissolved oxygen in the pond mainly comes from the photosynthesis of phytoplankton and the oxygen in the air dissolves directly into the water. However, in the cold winter, once the surface of the pond freezes, the oxygen in the air cannot dissolve in the fish pond. When heavy snow covers the ice, the sun cannot shine directly into the pond water, and the green plants in the water cannot carry out photosynthesis to produce oxygen. And most of the fish gather at the bottom of the water in winter, if the water quality is poor, the fish is weak, poor management and other cases, it is easy to cause fish hypoxia and suffocation to death. The methods of preventing fish from anoxia in winter are introduced as follows:

Sweep away the snow. During the freezing period in winter, in case of snowy weather, the snow on the surface of the fish pond should be swept away in time, so that the sun shines into the fish pond water, so as to ensure the normal photosynthesis of green plants in the fish pond water and release oxygen in time.

Break the ice and oxygenate. After the surface of the water is frozen, it is necessary to break the ice every morning and evening. Generally, each mu of fish ponds should break open 5 to 6 square meters of ice. At the same time, the crushed ice should be removed so as not to freeze quickly again.

Add fresh water. During the overwintering period, in addition to keeping the highest water level to increase oxygen and keep warm, fish should also be injected with new water regularly to improve the living environment of fish and increase dissolved oxygen, generally once every 20 days. If the water quality of the pond is poor and there is an aging phenomenon, the old water and harmful substances in the pond should be discharged in time, and each time the amount of water in the pond should be replaced by the original water, and then new water should be injected in time.

Fertilize properly. When the water quality in the fish pond is thin, a certain amount of inorganic fertilizer can be applied at noon on a sunny day, which can not only promote the growth and warmth of phytoplankton in the water, but also increase the dissolved oxygen in the water through photosynthesis.

Stir up the pond regularly. The aim is to loosen the bottom mud, mix the upper and lower water bodies, promote the rapid decomposition of harmful substances at the bottom of the pond, and keep the fish in a certain place of rest during the overwintering period, so as not to cause hypoxia. The method is to stir part of the pond bottom with a bamboo pole at noon on a sunny day and stir the other part after a period of time.

Sprinkle the potion. Put an appropriate amount of quicklime, bleach and other chemicals into the pond regularly to increase the oxygen in the fish pond and improve the water quality.