Why do carp black pits need to be cleaned regularly? Why can't you catch fish?

The black pit has a serious smelly bottom. Some small black pits have poor self-purification ability. Coupled with frequent fishing, a large number of bait piled up at the bottom of the pit. When the weather is hot, the bait left at the bottom of the pit will rot and deteriorate, and then the odor will be released at the bottom of the pit, destroying the water body. Fish don't like the bottom, and they don't like the mouth. In order to improve water quality and increase fish production, it is necessary to remove the Grimer at the bottom of the black pit and then put it back.

There are too many fish in the small black pit, and the fish are in a state of severe hypoxia. In some small black pits, if more fish are released and oxygen supply is not timely, the fish will be in an anoxic state. The more fish are stored in the pit, the more serious the anoxic state will be, mainly because the pit is too small and there is not enough oxygen. In order to alleviate this situation, we can only reduce the storage of fish, clear the pit on time and fish it out.

In order to improve profitability, the recycling cost of some large black pits is very high. They are designed as bottom pot pits, and the amount of fish is very large. Every time the fish is released 1 10,000 kilograms, the fish yield is generally controlled at about 60%, that is, 30%~40% of the fish are left in each fishing. After releasing a few fish, there will be a lot of fish in the pit. This kind of black pit generally does not stink at the bottom, and it will not be seriously deprived of oxygen. The purpose of cleaning the pit is to fish out the fish and then sell it to recover the cost directly. Therefore, many large black pit fishing grounds will clear the pits and catch fish on time.

When the weather is not suitable, fish are very sensitive to the weather change, because the weather change will directly cause the change of water temperature and air pressure, and then affect the dissolved oxygen content in water. Water temperature and oxygen are the environmental requirements for fish to survive. When the temperature is too high or too low, the temperature changes strongly and the air pressure is low, it is not suitable for fishing. Try to go fishing when the weather keeps fluctuating.

It is not allowed to find the water layer where fish eat in the same water body. Different fish have different swimming layers in different climatic conditions. In general, grass carp, bream, silver carp and silver carp all like to move in the middle and upper water; Crucian carp, carp, etc. I like to move and find food in the middle and lower layers of water. With the change of weather and water regime, its swimming layer will also change. Therefore, the swimming layer of fish should be identified according to the climatic conditions at that time.

I didn't grasp the timing of fishing. As I said before, the weather has a great influence on fish, but this influence will not last long, because fish can't eat it. Of course, this is only for crucian carp and carp. The weather is bad, and the fish won't eat for a while. At this time, it is necessary to better grasp the timing of fishing. Theoretically, fishing in the morning and evening is good, but special circumstances are special. If the fishing is not ideal in the morning and evening for a certain period of time, you can try it at noon or at night, and there may be surprises.