When the weather is sultry, why do all the fish in the pond surface?

Breathing at night is strong, and the water body is more likely to be acidic. The increase of gill mucus affects the opening of gill filaments and makes fish float. Especially in the area near the feeding platform, feeding in one place all the year round, the organic matter such as fish manure and residual bait is decomposed and fermented year by year, which reduces the pH value of local water, causing fish anorexia slightly and floating head symptoms seriously.

Spraying quicklime 15 ~ 20k g/μm into the pond can quickly increase the pH value by about 1 point or move the feeding table.

Long-term non-use of disinfectants in aquaculture ponds leads to a large number of suspended solids and harmful bacteria attached to fish gills, which leads to fish gills not breathing dissolved oxygen in water and floating heads.

Chlorine dioxide: the dosage of chlorine dioxide is 0. 1 ~ 0.3g/m3. When the pH value is 6 ~ 9, the bactericidal effect will be enhanced with the increase of pH value.

Bleaching powder: the water body is 1 ~ 1.5g/m3 based on chlorine-containing lime. When painting, it should be dissolved in water, filtered off the residue, and then sprinkled throughout the pool to prevent fish from swallowing bleach by mistake.

Povidone iodine: Sprayed in the whole pond, with the dosage of 4.5 ~ 7.5 mg/m3 water based on available iodine, every 2 days 1 time, and kept for 2 ~ 3 times.

Quicklime: 20 ~ 30g/m3 water is sprinkled in the whole pond. Due to the strong oxidation and alkalinity of quicklime itself, ionic ammonium in water can be easily converted into molecular ammonia, which will damage the gills of fish and directly kill fish, so ammonia nitrogen and nitrite in water are too high, so it is forbidden.

Hot weather and fatty water are easy to cause fungal infections such as gill mold. Generally, the floating head is serious during the day, especially after noon, and the situation improves at night.

A large number of rotifers, oblique tube worms, etc. Parasitic on the gill filaments of fish, causing floating head, often fidgeting and floating wildly in the pool.

Rot gill floating head caused by rotifer: spray with a mixture of copper sulfate and ferrous sulfate (5︰2) for 3 times, and the water concentration is 0.7 g/m.

Rotten gill floating head caused by Dactylogyrus: 0.2 ~ 0.3g/m3 of crystal trichlorfon or mebendazole (content: 10%). Dosage and precautions of drugs should follow the drug instructions.

The floating head caused by zooplankton (such as rotifers, cladocera and copepods) becoming the dominant population.

They are themselves high-quality live food for fry and bighead carp. Improper quantity of bighead carp in adult fish ponds will lead to excessive reproduction of zooplankton. When it reaches high density, they will compete with fish for oxygen, and even eat up phytoplankton, resulting in clear water quality, reduced dissolved oxygen, and floating heads of cultured fish due to lack of oxygen.

Kill zooplankton in the water near the pool at dawn time, and then feed water and fertilize again; Be sure to sprinkle it downwind or within 2 meters of the pool.

First of all, you can add unpolluted water to the pool for washing and pump out part of the pool water, but don't start the aerator, otherwise it will aggravate the death of fish. Secondly, detoxification can be carried out for different pollution sources to eliminate poisoning symptoms.

Too much unfermented organic fertilizer was applied to the pond in summer, and there were a lot of bacteria and fungi in the organic fertilizer, which caused hypoxia and floated in the water.

It is suggested to apply a small amount of phosphate fertilizer or biological fish fertilizer instead of organic fertilizer in intensive fish ponds in summer.

More than 80% of dissolved oxygen in water comes from photosynthesis of phytoplankton. Once there are fewer phytoplankton, the photosynthesis of water is weakened, and the dissolved oxygen is insufficient, resulting in floating heads. In this case, algae species and fertilizers are generally supplemented to the water body in time to cultivate the species and quantity of phytoplankton.