What are the precautions before fish farming

1. Diversify the shape of fish ponds: Fish ponds are often rectangular or dug-pond style, so as to give full play to the three-dimensional benefits of the aquaculture water body. The area of a single fish pond is generally about 0.067 hectares (mu, the same below), the pond depth is 2.5-3 m, the length-to-width ratio is 5:3, and the side slope coefficient is 2-3. In construction and shaping, it is possible to start with the easy and then the difficult, and build some transitional fish ponds, such as "concentric"-shaped, high-low type, "grid"-shaped, "field"-shaped and other shapes, among which the "concentric"-shaped fish pond is the most ideal transitional fish pond.

2. Promptly provide a matching irrigation and drainage system: the irrigation and drainage system is required to be built in step with the fish pond construction. In the planning and design, reserve the positions of the irrigation and drainage ditches. In the specific construction, focus on building the branch canals and field canals of the finalized fish ponds. The main canals, trunk canals and drainage ditches can be kept simple and left to be built when the whole project is completed. In terms of architectural form and materials, open channels may be used; for positioned and finalized channels, brick and stone materials can be used, while for those not positioned and not finalized, earth channels can be used. For fish-blocking facilities, it is best to use screens made of steel; the basic requirements are to hold the fish back, allow water to flow smoothly, and resist the impact of wind and waves.

3. Ensure the supply of energy and power: the engineering construction of each 0.067 hectares of fish pond is taken as one production unit, and according to the technical and economic index requirement of a designed unit yield of 750 kg: for each 0.067 hectares, support a total power of 1 kilowatt, equip 0.3 kilowatt aerators, with a power of 13 kilowatts; 1 axial-flow pump station with a diameter of 30 cm, and 3 submersible pumps with a diameter of 15 cm and a power of 2.2 kilowatts. This can ensure that in the high-temperature seasons of July, August and September, about 1/5 of the pond water volume can be exchanged every day, so that the quantity and quality of the pond water meet the needs of fish growth.

4. Scientifically choose the farming model: for newly opened fish ponds, because the water quality is clear and bland, it is advisable to choose a farming model based mainly on herbivorous fish, supplemented by omnivorous fish, and appropriately stocked with filter-feeding fish. The stocking amount is based on 1/6 of the designed unit yield, and the average size of the fingerlings is about 0.05 kg. The ratio of various fish is: grass carp and blunt snout bream: common carp, crucian carp and xenocypris: silver carp and bighead carp as 4:4:2, and a small amount of black carp and mandarin fish are also stocked (5-10 fish per 0.067 hectares). @#@233@#@ It is advisable to choose a farming model based mainly on grass carp, stocking 2500 grass carp summer fry per 0.067 hectares, 500 blunt snout bream summer fry, 1000 silver carp and bighead carp summer fry, and 100 Jian carp and high-back crucian carp summer fry; it is also possible to mainly raise carp fingerlings, stocking 3000 carp summer fry per 0.067 hectares, and raising 1000 summer fry of grass carp, blunt snout bream, silver carp, bighead carp, crucian carp and other fish.