Carp farming density should be reasonable, with appropriate polyculture of other fish species
AbstractThe recommended carp farming density is about 3000 jin per mu, and it is advisable to polyculture about 300 jin of black carp or silver carp and bighead carp together. The carp farming density mainly depends on the water quality environment, climate conditions and farming techniques of the location of the farm.
Farming density
With conventional farming methods, farming about 3000 jin of carp per mu of pond is optimal, and it is best to also polyculture about 300 jin of other fish species. Note that the number of polycultured fish must not be too high; if too many are stocked, disease outbreaks easily occur, and the losses in the later stage outweigh the gains. Generally speaking, black carp, grass carp, silver carp and bighead carp can all be polycultured with carp. At present, some mature farms in China can achieve a farming density of the four major Chinese carps reaching over ten thousand jin. However, different regions have different water quality, environment and climate, and there are also differences in farming techniques and investment. Conventionally, about 3000 jin per mu is generally farmed.
Polyculture precautions
With carp as the main farmed fish, the ratio of other polycultured fish is best at 6:4 or 7:3. The allowable stocking amount of carp is about 90-180 fish per 100 sq m of water body. However, because carp are highly competitive for food, if the pond is not mainly for farming carp but mainly for farming grass carp, the matching size of carp should be controlled at 25 g per fish, and the number per 100 sq m of water surface must not exceed 15 fish, otherwise other fish species will be unable to get food.
How to improve the farming efficiency of carp
1. Renovate the pond
Purpose: To increase water retention, raise the pond water level depth, expand the carrying capacity of the pond, and enable the pond to meet the conditions for carrying a high fish load. It is best to ensure that the water level depth is on average greater than 1 m 5 or more.
Method: According to the terrain conditions around the pond, first drain the pond water, then dig the pond deeper. The surroundings of the pond need to be hardened, or an impermeable membrane can be laid directly on the pond ridge.
2. Reasonably match the feed
In the case of high-density carp farming, without mature experience and techniques, carp growth rate is very likely to slow down. At this time, we need to appropriately adjust the carp feed combination to ensure that carp can reach the commercial fish size in time and then be sold on the market.
After visiting several large carp farms, it was concluded that feeding expanded carp feed 151# in the early stage and medium-grade carp feed 1012# in the later stage is a relatively effective combination. It can not only allow carp to obtain sufficient nutritional guarantee, but also has characteristics such as reducing the incidence of disease in carp, improving the fish body condition, and causing less water quality deterioration.
3. Aerator configuration
High-density carp farming easily causes pond hypoxia, so aerators are essential tools for farms. The commonly used aerators mainly include four types: paddle wheel aerators (daily aeration), microporous aerators (bottom aeration), wave-making machines (bottom-stirring aeration) and waterwheel aerators (water-pushing aeration).
Under high-density farming conditions, it is recommended: for every 10 mu, configure 5-7 units of 3.0kw paddle wheel aerators and 1 unit of 0.75kw wave-making machine; in the feeding area, configure 1 unit of 2.2kw microporous aerator and 1 unit of 1.5kw waterwheel aerator.
From 30 minutes before feeding to 30 minutes after feeding, the microporous aerator and waterwheel aerator should be turned on. On sunny days at noon, turn on the wave-making machine for more than 3 hours. At night, turn on the microporous aerator and paddle wheel aerator to ensure the minimum dissolved oxygen is above 3mg/l. Only in this way can carp obtain enough oxygen.
4. Improve water quality
As the saying goes, to farm fish first farm water, and to farm water first farm mud; prevention first, prevention is more important than treatment, and farming is more important than prevention. This farming concept has been summarized by many farmers over the long term, and it is very reasonable. In the case of high-density carp farming, it is recommended to regularly and alternately use water-conditioning products such as Golden Peptide, Feed Partner 2 and Feed Partner 4 for algae and bacteria regulation, cultivating beneficial algae or bacteria, etc.
In the middle and late stages of farming, timely splash Bottom Improvement Clean and Nitrite Clean to improve the oxygen solubility of the water, improve the bottom quality, and maintain good water quality. At the same time, every half month to 20 days, use disinfectants such as chlorine dioxide and bleaching powder once for disinfection. Alternately use the intestinal protection and immunity package (that is, the combination of Qishen powder, lactic acid bacteria and vitamin c) and the liver and gallbladder protection package (that is, the combination of Sanhuang powder, vitamin c and Gandanshuling) to carry out liver, gallbladder and intestinal maintenance for crucian carp, making the crucian carp body healthier.