Master four solutions to the harm of excessive silt in fish ponds

Fish pond

After a period of time, due to the frequent deposition of some residual bait, fertilizer, dead organisms, fish feces and other organic matter, coupled with the mixing of sediment, the bottom of the pond gradually formed a certain thickness of silt. When the thickness of the silt exceeds 20 cm, it will have a very adverse effect on the pond fish.

I. the harm of excessive silt in fish ponds

The yield of farmed fish in ① is low. Due to the increase of silt thickness and the elevation of the bottom, the water capacity of the pond becomes smaller, the water temperature of the pond increases, and the yield of food organisms decreases, which is not conducive to the high yield of close culture.

② is easy to produce floating head and dead fish in floodpond. There is a large amount of organic matter in the sludge, which constantly consumes the dissolved oxygen in the water body in the process of decomposition. The more silt, this will lead to insufficient dissolved oxygen in the lower layer of the pond and the whole body of water. Especially in the event of strong wind, heavy fog, overcast rain, thundershowers, etc., the bad climate with low air pressure will cause the fish in the fish ponds to flood the ponds due to serious hypoxia.

③ is easy to form "old water", which makes the quality of fish poor and its resistance reduced. There is a large amount of organic ammonia in the organic matter of the sludge. When the content of ammonia in the sludge is too high, it will continue to spread into the water, which provides a material basis for nitrification and deamination. When there is insufficient dissolved oxygen, it will affect the smooth progress of nitrification, slow down the speed of nitrification, aggravate the accumulation of ammonia, lead to the aging of water body, decrease the growth performance, frequent diseases, decline in yield and quality, fish deformation and bending in livestock, fish with peculiar smell, and even the death of a large number of fish.

④ is easy to cause fulminant fish disease. There are many diseases such as parasites and bacteria in the sludge. When the fish pond environment deteriorates, the acidity increases and various pathogens breed. At the same time, in the adverse environment, the stress resistance of fish is weakened, and fish disease is easy to occur.

II. Solutions

① removes too much silt from the pond. In each production cycle, usually after 3-4 years, the pond silt with a depth of 20 cm can be retained in order to keep the fish pond fat and water quality relatively stable by using the dry and rainless season in winter and spring.

② lets the bottom of the pool be thoroughly exposed and frozen. The fish ponds that have been desilted in winter can make use of their free time to drain the pond and let the bottom of the pond be blown, sunburned and frozen. After sunlight and weathering, a small amount of silt at the bottom of the pond becomes relatively dry and loose, and at the same time, it can kill pathogens and parasitic eggs, improve the ecological environment of the pond, improve the pond fertility, and lay a good foundation for high yield and harvest in the following spring.

③ releases quicklime. The application of 100 kg quicklime per mu in the pond can not only kill the fish parasite eggs and pathogens hidden and propagated in the mud, but also increase the pH value and clarify the pond water. In addition, quicklime turns into calcium hydroxide after meeting water, and absorbs carbon dioxide to form calcium carbonate. Calcium carbonate can make the sludge loose, improve the aeration conditions at the bottom of the pool, and accelerate the decomposition of organic matter by bacteria.

④ rotates fish farming and growing crops. This can make the silt more fully dry, rely on the developed roots of terrestrial crops, make the land loose, facilitate the mineralization and decomposition of organic matter, and better improve the bottom of the pond. In addition, the growing green crops can also be used as high-quality green manure for fish ponds.