After winter, drain the water in the pond, dig out a layer of sludge, and then expose it to the sun, so as to eliminate pests. If it is not possible to dry the pond after catching fish and crabs in winter due to production needs, a part of the sludge at the bottom of the pond can be extracted by a blowdown machine, or the sludge can be picked up by a bamboo basket and shipped to the shore as plant base fertilizer, killing two birds with one stone, reducing the amount of sludge at the bottom of the pond and helping to reduce the breeding of germs. At the same time, weeds covering the bank should be removed to reduce the places where insects lay eggs. At the same time, reinforce the pond foundation to prevent leakage.
Second, the chemical pool cleaning
1. Quicklime cleaning pond: After the fish and crab pond is repaired, the pond is cleaned with quicklime, with 50- 100 kg of quicklime per mu, and the dry powder is evenly discharged to the pond bottom or pond bottom and pond foundation, and then 4-6 cm of clear water is poured. The next day, mix the mud and lime slurry at the bottom of the pool evenly with a long-handled rake to give full play to the disinfection effect of quicklime.
Some fish and crab ponds can be cleaned with water if they can't go out before cleaning the pond, or if the original pond water can't be replenished after being drained. Quicklime 120- 150kg can be used per mu of water surface (1m water depth), which can be put into a small boat, turned into mortar after adding water, and splashed all over the pond while it is hot.
After cleaning and disinfecting the pond for 7 days according to the above method, put the pond water to the required water level, then dissolve 500 grams of crystal trichlorfon in water per mu (1 meter depth) and spread it all over the pond to kill parasites in the water; After 3 days, the water body was disinfected with chlorine dioxide. Generally, each mu (1m water depth) is mixed with Party A and Party B 1 bottle (500ml), and sprinkled all over the pond. After 2-3 days, when the water turns light green, fry and crab fry can be added.