Winter fish can not be ignored calcium phosphorus

Some people think that winter fish ponds have low water temperatures, low fish activity, slow metabolism, low food intake, and low water quality requirements. Fish ponds do not require calcium and phosphorus, thus neglecting winter fish farming for calcium and phosphorus. The application. In fact, this is a misunderstanding. Under low temperature conditions in winter, increasing the content of calcium and phosphorus in water is more conducive to improving water quality conditions and physiological metabolism of fish. It can not only enhance the cold-resistance ability of fish, increase the survival rate of overwintering, but also maintain the normal physiological indicators before overwintering, give full play to the growth potential after the spring, and increase the aquaculture production and economic benefits.

1. The choice and correct application of lime

In the aquaculture production, calcium lime is added to the water by applying quicklime. This method is not only labor-intensive but also difficult to handle, and particularly poor in safety. After years of exploration, we believe that a more feasible method is to dig a pit near the pond. The size of the pit depends on the area of ​​the fish pond, generally 5 to 10 为. It is advisable to use bricks to protect the bottom and the surrounding area. After being filled with water, the quicklime is put into the pit first, and the bath bubble 3~5 angels become mature lime, which is then diluted with water and mixed into a low viscosity emulsion shower. Usually 15 to 20 days spilled once, the dosage is 30 to 50 grams of cooked lime slurry per cubic meter of water. This method can also be used to disinfect clear ponds and its effect is better than using quicklime.

2. Phosphate selection and correct application

There are many types of phosphate fertilizers used in fishery production in China. From the point of comprehensive analysis of the prices of effective nutrient components and technical feasibility, it is necessary to select one grade of superphosphate containing 18% of available phosphorus or 16% of available phosphorus. Grade superphosphate is preferred; heavy superphosphate or monoammonium phosphate may also be used in areas where the aquaculture surface is large and the economic strength is strong. Their common feature is that the aqueous solution is weakly acidic and cannot be applied at the same time as lime. It is usually applied for 4 to 6 days before applying phosphate fertilizer. From the experimental situation, the application amount of phosphate fertilizer was calculated to be 0.3% of available phosphorus per cubic meter of water. The interval between application of phosphate fertilizer and lime application time is consistent. No matter which type of phosphate fertilizer is used, the water must be sprayed evenly to increase the utilization rate. Don't waste time by trying to save the phosphate fertilizer and sinking into the pool bottom.