Five methods of clearing ponds before the release of fish species

Before stocking, the culture pond must be cleared to kill all kinds of ferocious small wild miscellaneous fish, harmful aquatic animals and plants, parasitic eggs and pathogenic bacteria in the pond, so as to create a good environment for the growth of adult fish. The following five pond cleaning methods are introduced:

First, clear the pond with quicklime. When the pond is cleared by drainage (that is, the pond water is drained to 5 cm deep and then the pond is cleaned), 60kg / mu of quicklime is used in the pond; when the pond is not drained, 125kg / m of deep water is used in the pond (200ppm). When using quicklime to clean the pond, it is necessary to dissolve the quicklime with water, and then immediately sprinkle it evenly into the pond.

Second, clean the pond with bleach. When clearing ponds with drainage, use 415kg per mu, and 1215kg per mu of deep water (25ppm) if there is no drainage. When in use, it needs to be dissolved with water and sprinkled in the whole pool.

Third, clear the pond with the mixture of quicklime and bleach. When cleaning ponds for drainage, 2kg of bleach and 30kg of quicklime are used per mu of water surface; when there is no drainage, 5kg of bleach and 60kg of quicklime are used per mu of deep water. The usage can refer to the usage of quicklime and bleach.

Fourth, use fish rattan essence to clear the pond. When clearing ponds without drainage, 1.3kg (2ppm) is used per mu of pond per meter of deep water. When in use, add water 10: 15 times dilution and sprinkle evenly all over the pool.

Fifth, clear the pond with Croton. When clearing ponds without drainage, use 5 kilograms (9ppm) per mu of pond per meter of deep water. Before use, the Croton must be mashed and milled into a jar, then sealed with 3% salt water and soaked for 3-4 days, diluted with water and sprinkled with slag and water throughout the pool.

Among the above-mentioned drugs, quicklime has the best effect of cleaning the pond, which can not only kill and sterilize, but also loosen the subsoil, improve the aeration condition of the soil layer and fertilize the pond water.

When using the above agents to clear the pond, we should pay attention to the following: (1) before use, it is necessary to test whether the drug is effective. (2) it is required to clear the pond about half a month before stocking. (3) the failure time of the above drugs is 5-10 days (bleaching powder is about 5 days, Croton is 10 days). For the sake of safety, for fish ponds that have been cleared with drugs, try to raise a few fish (commonly known as test-water fish) before stocking, and it is proved that the toxicity has indeed disappeared before a large number of fish can be released.