How to control water mildew in fish

Water mildew is the most common disease in aquaculture. at present, malachite green is widely used to prevent and cure malachite green. because malachite green has carcinogenic and teratogenic effects, malachite green has been included in the list of prohibited fishery drugs. Now, for the prevention and control of water mildew, what measures should we take?

1. Clear and disinfect the pond with quicklime before stocking. Every 667 square meters of the pond with 100 kilograms of quicklime, water after the whole pool sprinkled evenly, which can significantly reduce the probability of the occurrence of the disease.

2. Avoid fish injuries. In the process of fishing, transportation and stocking, the operation should be light and avoid fish injury as far as possible. In addition, fish stocking avoids cold weather as much as possible.

3. Fish seeds are soaked and sterilized. Soak the fish fry in 3%-5% salt water for 5 minutes for 10 minutes before putting them into the pond.

4. Sprinkle all over the pool. When fish in the pond suffer from water mildew, we can use the following methods to treat them.

When the water depth of ① is 1 meter, every 667m2 of water is mixed with 2.5kg of Polygonum polygonum, 0.5kg of black raspberry and 2kg of maple poplar leaf, diluted with water and sprinkled in the whole pool, once a day for 2 or 3 times.

When the water depth of ② is 1 meter, use 5 kg of gladiolus juice and 1 kg of salt on every 667m2 of water, add 20kg of human urine to mix evenly, and sprinkle it in the whole pool after melting water.

③ was sprinkled evenly in the whole pool with methylene blue water, so that the methylene concentration in the pool water reached 2: 3 ppm after 3 days and 4 days later.

5. Matters needing attention in artificial reproduction.

① tries not to choose injured fish as parent fish. If injured parent fish enter the pool, sulfonamide ointment must be applied to the affected area.

Prevention and treatment of water mildew in ② fish eggs. One is to try to improve the fertilization rate of fish eggs. Second, the fish nest is soaked in 3%-5% formalin solution for 2-3 minutes or 1%-3% saline solution for 20 minutes. The third is to sprinkle methylene blue aqueous solution in the water hatched by running water to make the concentration of methylene blue reach 5ppm.