1, water, disinfection, fertilizer and water
After cleaning the pond with quicklime, filter it with 40 mesh 10- 15 five days before the shrimp fry are released, with 50cm of water and 60-80ml/ mu of heavy iodine (mainly compound high iodine). Rice is mixed with water, and the whole pool is sprinkled with disinfectant. Shi su Fei Bao 1 kg/mu. Rice, diluted with 10-20 times of pool water, evenly sprinkled in the whole pool, and applied with 200g/ mu of concentrated photosynthetic bacteria? Rice, activated by adding water for 0.5- 1 hour, and then sprinkled with pool water. A week or so, a large number of red worms (cladocera) can breed and cultivate shrimp seedlings.
After the shrimp goes down to the pond, it only enters the water without draining, and the accumulated water can reach about 5cm every day. According to the water color and weather conditions, Renzhong Sufeibao should be applied again to keep the transparency of the pool water 30-40 cm, and the water color is tender green or dark brown. If the fertility of pond water is well controlled, the red worms bred in the pond can meet the nutritional needs of shrimp seedlings without feeding for one month, and the shrimp can grow to 4-5cm in that month.
Step 2 change water
In the middle stage of culture (the shrimp is 5-8cm long), the amount of bait and feces increases and the temperature rises gradually. According to the change of water color and transparency, a small amount of water can be changed, and the amount of water changed is controlled within 10%. When the residual bait and feces reach the maximum value in the later stage of culture (shrimp is more than 8cm long), the water exchange rate should be increased, and the water exchange rate should be controlled at about 20% with a transparency of 40-50cm.
3. Adjust the pH value of the pool water
High pH value is easy to cause symptoms such as difficulty in molting and loss of appetite. Low pH value can easily lead to bad phenomena such as shrimp breathing difficulties, yellow cheeks and swollen cheeks, so it is necessary to check the water quality frequently and deal with any abnormal phenomena in time.
If the water quality is slightly acidic (the pH value is lower than 7.0), it needs to be adjusted with quicklime, and the dosage is 8- 10PPM (5-7kg per mu) for 3 days.
If the water quality is alkaline (pH value is higher than 9.0), it is best to drain 20-30cm of pool water if possible, add 20-30cm of fresh water, and then use Jianganling (glycyrrhizic acid as the main component) and 1m 250g of water per mu to splash water, which can be used for 2-3 times as appropriate.
4. Reasonable use of aerator
The opening principle of the aerator in semi-intensive pond is: open at noon on sunny days, open in the early morning on cloudy days, open at midnight on rainy days, close at night, open the floating head early, open more when there is no wind, open less when there is wind, open more when there is high temperature and open less when there is low temperature.
Start-up principle of aerator in intensive culture pond: refer to the above-mentioned start-up principle in the early stage of culture (shrimp body length is less than 5cm) and the middle stage (shrimp body length is 5-8cm); In the late stage of culture (the shrimp is more than 8cm long), it is turned on all day except half an hour before feeding and 1 hour after feeding.
5, regular use of microbial agents
In the peak season of shrimp growth, the water quality is seriously polluted because of feeding a lot of bait. The conventional method is to change a lot of water, but it is easy to cause stress reaction of shrimp. In practice, EM bacteria and ultra-concentrated compound Bacillus can be used to adjust the water quality, and the effect is very ideal. Living bacteria can effectively decompose organic matter, reduce the concentration of ammonia nitrogen, nitrite and hydrogen sulfide in water, reduce water exchange capacity and maintain water quality stability. In the middle stage of culture (the shrimp is 5-8 cm long), 250 g/mu of EM bacteria is selected at noon on sunny days. Rice, activated for 1-2 hours, sprinkled with water in the whole pool, and used once every 10- 15 days; In the late stage of culture (shrimp is more than 8cm long), ultra-concentrated compound Bacillus is used to improve the transparency of pond water and improve the water quality and sediment.
6. Use glucose and Vc to transfer water.
After heavy rain or windy weather, the water is turbid and shrimp is prone to stress reaction. Put glucose 2kg/ mu? Rice and Vc200g/ mu? Rice can reduce the stress response of shrimp and increase oxygen.
Through the implementation and flexible application of the above measures, the water quality of shrimp pond can basically reach "fat", "live", "tender" and "cool", which meets the requirements of the rapid growth of Penaeus vannamei and provides a strong guarantee for the high and stable yield of shrimp.
Water quality treatment method
3 dark green
The color of water body appears under the condition of strong light and long-term eutrophication of sediment, which means that the water quality will change suddenly in a period of time. The treatment method is: drain water at night 12: 00 or after 4: 00 ~ 5: 00 in the morning, and return water at around 7: 00 in the morning, with a water displacement of about 20cm each time until the sewage discharged from the bottom no longer stinks and turns black. If frequent large-scale water exchange does not cause abnormal reaction of prawns, the method of large drainage and irrigation can be used to change water. After changing the water, disinfect the water with quaternary ammonium salt complex iodine, and spray 30 ~ 50kg/667m2 zeolite powder, dolomite powder or other water quality improvers or ecological water-retaining agents the next day. After the third day of disinfection, beneficial live bacteria can be put in. If it is difficult to change water or the method of changing water is not adopted, high-quality disinfectant can be mixed with water and sprayed.
Second, fertilizer and hydroponic bait
1, inorganic fertilizer: urea 2-3 kg/mu, phosphate fertilizer 1- 1.5 kg/mu. Top dressing 1 time for 3-5 days, with the dosage of13 of the first time, and fertilization at 9- 10 in the morning.
2. Soymilk: Soak soybeans 10 kg in water per mu, grind them, spray them, and pour them 1 time after 2-3 days.
3. Fertilizer and water elements in hydroponics: biological fertilizer and high-efficiency fertilizer and water elements are used, and the dosage is 1-2kg/ mu. The transparency is 30-40cm, and the water color is yellow-green or yellow-brown. "It is worth noting that Litopenaeus vannamei has a wide range of feeding habits, preying on zooplankton and phytoplankton in the water at larval and larval stages. 」。 Under the condition of artificial culture, adult shrimp mainly eat pellet feed and soybean meal, and the requirement of protein content in feed for Penaeus vannamei is 20-30%. At the same time, the absorption rate of plant protein in soybean meal is higher than that of Macrobrachium rosenbergii and Penaeus China.
Third, water quality supervision.
The methods of water quality adjustment are: (1) adding water. At the initial stage of putting shrimp seedlings into the culture pond, add 3-5 cm of water every day to gradually reduce the salinity. When the water depth reaches 0.8- 1 m, after the adaptability of shrimp seedlings to fresh water environment is enhanced, water is added to the depth of 1.2- 1.5 m at one time. ⑵ Oxygenation: Turn on the aerator every morning and evening to make sure there is enough dissolved oxygen in the water. It takes 24 hours to inflate in rainy days. ⑶ Reduce stocking density appropriately to obtain adult shrimp. ⑷ Mixed culture with other species and interplanting loach with a small amount of silver carp and bighead carp can achieve the purpose of increasing oxygen and purifying water quality. 5. Water control: If shrimp larvae are fed with feed for a long time, the water quality will exceed the standard. Biological agents, such as photosynthetic bacteria and Bacillus, should be used to improve the water quality.
Fourth, water quality management.
1, early management. Water should be replenished mainly within 1 month after sowing, generally 5- 10cm every 2-3 days until the water depth reaches 1.5m, and biological agents should be used to improve the water environment in the pond.
2. Middle and late management. (1) Apply photosynthetic bacteria. After application in shrimp ponds, harmful substances such as ammonia nitrogen, hydrogen sulfide and organic acids can be quickly eliminated, the pH value can be balanced, and the quality of pond water can be improved. ⑵ Application of EM bacteria in water purification. A variety of exotic living bacteria make up for the deficiency that photosynthetic bacteria can not directly use macromolecular organic matter, biological corpses, residual bait and feces, and have the functions of oxidation, nitrification, denitrification, phosphorus dissolution and nitrogen fixation. It can not only purify water quality, but also provide nutrition for the reproduction of unicellular algae. Bacteria breeding in the pond can inhibit the growth of pathogenic microorganisms and reduce shrimp diseases. ⑶ PSB or other biological agents should be applied regularly in the main pond to improve the water quality. PSB sprays 4× 1 0-6 bacterial liquid in the whole pool once a week, or mixes it with food, and the dosage is 5% of the feeding amount. ⑷ Grasp the transparency and pH value. At the initial stage of stocking, the transparency of shrimp ponds is controlled at about 30 cm, and it is 35-40 cm in the middle and late stage; During the culture period, quicklime 1 time, 5- 10 kg per mu, was applied every 20 days to stabilize the pH value at 7-8, thus increasing the calcium content in the pond water and meeting the needs of shrimp growth.
On this basis, it is necessary to start the machine frequently, patrol the pond frequently, carefully record the feeding management, regularly detect the quality and growth of shrimp, and monitor the main factors of water environment. At the same time, reasonable fertilization is needed to propagate unicellular algae, maintain its reasonable population density, ensure the normal material circulation and energy flow of water body, and realize ecological regulation.