Traditional Culture Encyclopedia - Weather forecast - I was in a hurry, and the day after the fish floated over, there were dead fish one after another.

I was in a hurry, and the day after the fish floated over, there were dead fish one after another.

Judgment of fish floating head

First, the time when the floating head starts. Floating head is a frivolous head at dawn. After sunrise, phytoplankton photosynthesis produces oxygen, dissolved oxygen in water increases, and the floating head may gradually disappear; If it starts in the middle of the night, it is a heavy floating head. At night, the dissolved oxygen in the water will decrease, and there will be a long time before sunrise the next day, and the floating head will only become more and more serious and even flood.

Second, the floating head range The floating head of the fish in the central part of the pond is a floating head; If it extends to the edge of the pool, if there is a fish floating head on the whole pool surface, it is a heavy floating head.

Third, the reaction when frightened, the floating fish is slightly disturbed (high-five, or illuminating the pool surface with a flashlight), that is, sinking, stopping and floating, which is a slight floating head; If the fish doesn't sink when it is frightened, it means that the water is extremely anoxic and it is a heavy floating head.

4. The species of floating fish are anoxic floating heads, and the order of various fish is different: tilapia, bream and bream floating heads, and wild fish and shrimp floating heads on the shore are mild floating heads; The floating heads of silver carp and bighead carp are general floating heads; Grass and herring have heavier floating heads; Carp floating head is more serious; If grass carp and herring are on the shore, stranded in shallow water, unable to swim, pale and dead, it means that the flood is about to begin.

Floating head prediction

There are certain signs before the fish floats, which is predictable.

1. The weather is predicted according to the weather forecast and the weather conditions of the day. At night, when there is a thunderstorm, the weather turns cloudy and rainy, and the fog stays sunny for a long time. Once the weather changes, Rosty Yi may float.

Second, when the weather changes from April to May, fish are prone to dark floating heads; It is easy to float in rainy season; The weather changes dramatically in summer, which is easy to cause floating head.

Third, the eating situation of fish When checking the food field, it was found that the bait was not eaten within the specified time, and no fish disease was found, indicating that the oxygen conditions in the pond were poor and floating heads might appear.

Prevent floating head

1. Applying biological fish fertilizer: 2-3 kilograms of biological fish fertilizer can be applied per mu of water surface every month, which can effectively increase dissolved oxygen in the pool and prevent floating head. Biological fish fertilizer must be soaked for 5-6 hours before application.

2. When it is predicted that floating head may appear, stop fertilization, control the feeding amount, and take measures to increase oxygen.

Rescue floating head

The dark floating head often appears in the early stage of feeding, and it is also the first floating head of fish in the pond. It is necessary to replenish fresh water or start the aerator in time, otherwise the fish will die one after another because they have not adapted to the anoxic environment.

Generally, after the water temperature starts to float at 25-30℃, it can be delayed for 2-3 hours without danger. After the water temperature starts to fluctuate above 30℃ 1 hour, oxygen-increasing measures must be taken immediately.

When the floating head is heavy, an aerator should be used for aeration (3 kW impeller aerator is used for 5- 10 mu of water surface) or a large-caliber water pump should be used to add water, so that the water sprayed by the water pump will be washed out of the plane to form a water flow, so that floating head fish can gather in this water flow with high dissolved oxygen to avoid dead fish in the pond.

If there is no oxygen-increasing equipment, the temporary first-aid measures are: throwing yellow mud water into the pool and adding salt water; Yellow mud water with urine, salt water, alum water, gypsum powder, etc. Through the above measures, organic particles and colloids suspended in water can be coagulated and precipitated, so as to reduce the consumption of dissolved oxygen and the harm of floating head.