1, remove the silt at the bottom of the pond. Generally, after a year or more of fish farming, tens of centimeters of silt will be deposited at the bottom of the pond, which contains a lot of residual bait and fish feces (humus for short). When the weather is hot, the water temperature rises, and humus consumes a lot of oxygen, which leads to the deterioration of water quality and affects the normal feeding and growth of fish. Therefore, it is necessary to remove the silt at the bottom of the pond manually or mechanically after commercial fish are caught in the market in winter.

2. Repair dams and pond slopes. After several years of fish farming, pond slopes and dikes have collapsed to varying degrees and need to be renovated. When the silt at the bottom of the pond is removed, the silt can be placed on the embankment and the embankment slope. When it is slightly dry, it can repair the edge of the pond, plug the leak, reinforce the embankment, and crush the clods tightly. Plant green feed after spring.

3. Expand the area and deepen the depth. Some old ponds have irregular shapes. The mounds and empty flats around the pond can be excavated and arranged to make the pond as rectangular as possible to expand the feeding area; Some two small ponds are connected together, and the broken and collapsed pond ridge in the middle can be removed to increase the water surface (that is, they are combined into one). At the same time, the bottom of the pond becomes deeper and the ridge of the pond becomes higher, thus increasing the depth of the pond.

4. Transform the water inlet and outlet system; Cleaning, silting and repairing water inlet and drainage channels; Maintain large and small gates; Overhaul the water pump and other machinery to make the water inlet and outlet system unimpeded, and make all preparations for normal production in the coming year. Finally, clean the pond, and it is best to clean the pond with drugs. When new water is injected, it should be filtered with a dense mesh to prevent wild fish and enemies from entering the pool. After the efficacy disappears, the cultured fish can be put into the pond.

The content of this article comes from: The History of Science and Technology Development of Agriculture and Animal Husbandry in Tibet by China Agricultural Publishing House.