Integrated control technology of fish floating head

From June to October every year, the temperature is high and the weather is muggy. If the fish stocking quantity is too large and the water quality is bad, it is easy to cause anoxia floating head, or even suffocate to death. In severe cases, 1-2 hours can cause all the pond fish to die. Therefore, correctly analyzing the causes of fish floating head and identifying the omen and severity of fish floating head are of great significance to strengthen daily management and rescue Fantang in time.

(1) the reasons for the floating head of fish.

There are mainly the following aspects: (1) excessive feeding and fertilization blindly, resulting in excessive fertilizer of water quality, mass reproduction of plankton, increase of oxygen consumption of organic matter and decrease of dissolved oxygen. (2) the natural conditions are poor and the stocking density is too high, resulting in insufficient dissolved oxygen in the water. (3) the silt at the bottom of the pond is too deep and the water quality deteriorates. (4) without adding new water for a long time, the water quality is fat and aging. (5) the water body is polluted and contains some toxic and harmful substances. (6) it is easy to deteriorate the water quality if the water temperature is too high because it is sunny for a long time. (7) the water quality is more fertile, the light is poor in overcast and rainy days, the photosynthesis of phytoplankton is weak, and the supply of oxygen in the atmosphere is less.

(2) the harbinger of a fish floating head.

Fish floating heads often occur in muggy and rainy weather in summer and autumn, especially at night or dawn. Muggy weather, strong light, sudden thundershowers, high temperature; continuous rain, muggy, windless or foggy weather, low pressure and weak light; long sunny without rain, large amount of bait fertilization; water quality is too thick, water color abrupt change, transparency becomes smaller; fish without disease and food intake suddenly decreases, a large number of plankton die and decompose; fish cluster upper layer of water, scattered swimming, visible bursts of spray The sudden deterioration of water quality and the concentration of small fish and shrimp swimming on the shore are a harbinger that the fish will float in the pond.

(3) Identification of fish floating head.

The degree of hypoxia in the water can be judged according to the severity of the floating head of the fish. The specific distinction is as follows: (1) when you see a fish floating head in the pond in the early morning, clap your hands or throw a small stone into the pond, the fish sinks immediately when you are frightened, or automatically sinks soon after the sun comes out, indicating that the hypoxia is not very serious and belongs to light floating head. (2) if the shock cannot react or does not sink after 9 o'clock, it means that the hypoxia is serious and belongs to light floating head. (3) if the fish expands from the middle of the pond to the shore in the middle of the night, it indicates a heavy floating head. (4) from midnight to the middle of the night, herring and grass carp are concentrated on the shore, all floating heads, shortness of breath and weakness, indicating that the fish will soon flood the pond.

(4) Prevention of floating head of fish.

(1) do a good job in water quality management. To achieve the "three maintenance", that is, to keep the transparency of the water about 25 cm; to keep the pool water with enough dissolved oxygen; to keep the pool water "fat, tender, cool and alive". Pay attention to the frequent injection of new water, it is best to maintain a micro-flow state is better, and timely removal of residual bait in the pond. (2) to improve the ecological environment of fish ponds, from shallow reservoirs to deep reservoirs, from dead reservoirs to living reservoirs, and from small reservoirs to large reservoirs. (3) equipped with aerator. Generally, an aerator is installed on the water surface of 0.2 to 0.3 hectares. The start-up time of the aerator is generally open at noon on a sunny day, open in the morning on a cloudy day, open in the middle of the night on a continuous rainy day, and do not open in the evening; the floating head opens immediately; during the peak fish growing season, keep on opening every day. It requires a long boot time in the evening or midnight and a short boot time at noon. (4) Drug prophylaxis. With the aging of water quality and excessive reproduction of plankton, quicklime, trichlorfon, copper sulfate and other drugs should be used in time to regulate the water quality and kill too much plankton. When the water quality is slightly acidic, it can also be adjusted with quicklime. (5) the pond mud is stirred by the method of pulling net and people going down to the pond to promote the decomposition of organic matter and often destroy the stratification of water. Generally every 10 days or so, the pond stirring time is carried out at noon on a sunny day for 1 hour, and 15 kilograms of quicklime is used for every 0.067 hectares of water every 20 to 30 days, and then sprinkled throughout the pond to improve the water quality. (6) reduce the stock of fish in the pond. For the frequent occurrence of serious floating head fish ponds, it is necessary to catch some fish on the market in time. And get rid of all kinds of wild fish.

(5) the rescue of Fantang.

As soon as you find any signs of fish floating, you should be treated immediately. Light floating head, can immediately add new water to the pond, and reduce the amount of bait. For fish ponds with serious floating heads, it is necessary to turn on the aerator in time and inject new water. if there is no aerator, you can use a wooden stick to beat the surface of the water to increase oxygen or drive a stake in the fish pond and tie a hollow bamboo tube with a bowl mouth thick and about 1.5 meters long to irrigate the bottom; or add ammonium sulfate and calcium peroxide to increase oxygen in order to oxidize organic matter and remove toxic substances. At the same time, some slurries that can precipitate organic matter and absorb toxic substances are sprinkled into the water. Generally, the dosage for every 0.067 hectares of water depth is as follows: gypsum powder 3kg, alum 3kg, salt 10kg. Yellow mud salt water (10 kg of yellow mud and 10 kg of salt), 10 kg of yellow mud and 10 kg of human urine, 5 kg of yellow mud and 7.5 kg of limewater can relieve the floating head of fish.