In aquaculture, the survival rate of fish and shrimp is the most critical to the cost of aquaculture. It is estimated that the survival rate of 40% shrimp is about 0.4 times that of 65438+70% shrimp when 320,000 shrimp seedlings are cultured per hectare. Disease and water quality changes (also known as floating head or flood) are the main causes of a large number of deaths of fish and shrimp. Fish and shrimp inhabit vast waters, and most of their diseases are caused by the aging soil and poor water quality in ponds. In fact, if the growth environment is good and the fish and shrimp are strong, the existence of pathogens alone is not enough to cause too much harm, so it is almost impossible to control the fish and shrimp diseases only by drugs after the onset. Only by fully understanding the situation of aquaculture ponds at ordinary times, reasonable scheduling and supplemented with preventive additives can the serious losses caused by fish and shrimp diseases be effectively eliminated. Our ancestors have accumulated long-term experience and deeply understand this truth. Tell us? Are you pregnant? ⒀? At present, this old adage is more important for modern intensive farming with high stocking density. It is undoubtedly the primary task to take preventive measures at any time to prevent the pond soil from aging, maintain a good water quality environment, improve the survival rate and greatly reduce the breeding cost. Therefore, collect the research experience of our company's technical team, consult advanced aquaculture experts and scholars, and compile a technical manual for shrimp culture for your reference.

Second, the field

The environment, location, shape, equipment and water source of aquaculture ponds have great influence on water quality. This may also be related to shrimp farming. During the breeding period, the contents of suspended solids, hydrogen sulfide (H2S), ammonia (NH3) and nitrite (NO2-) in the water are too high, and the lack of dissolved oxygen will cause the grass shrimp to have urgent urination, reduce the growth rate and feed efficiency, and become a place for secondary infection of microorganisms and bacteria. Therefore, the site selection must give priority to the water quality and quantity of aquaculture ponds. These two factors can also determine the output per unit area. In addition to the general water quality analysis, it is also necessary to detect the contents of metals such as copper, iron, zinc and manganese. Generally speaking, if it is inconvenient to change water in a grass shrimp culture pond, the ammonia concentration will easily increase. The time, frequency and salinity ratio of water change must also be considered in a culture pond with convenient water change. Therefore, the stocking density, yield per unit area, site selection and water source of grass shrimp are closely related. The site selection can be analyzed and considered from the following points:

1. Location:

It is advisable to choose a place close to the seaside where natural seawater can be used for aquaculture.

2. Water source:

Seawater can be introduced from the intake ditch by using the tidal range of seawater, which is rich in water resources, and salt water, fresh water or estuary can be extracted through underground wells.

3. communication:

Choose a place with good road conditions and convenient transportation of feed, shrimp seedlings and adult shrimp.

4. Water quality:

Carefully choose unpolluted water sources and places with low iron and heavy metals content.

5. Substrate:

It can be divided into semi-muddy soil, argillaceous soil, sandy soil and gravelly soil, and it is not permeable, and the permeable place should be tamped with new soil, otherwise algae will not be easy to cultivate.

6. Electricity:

The power supply should be sufficient for water pump, waterwheel, inlet and outlet water and emergency use, and it is best to equip with diesel generator or diesel pump to prevent power failure.

Third, the construction of ditches in aquaculture ponds

1. area and shape:

The area of each pond is preferably between 0.5 ~ 1 A, and the shape is square. It is best not to have irregular shapes such as concave and convex, otherwise it will easily lead to insufficient water flow, reduced dissolved oxygen, temperature stratification and methane accumulation. Therefore, it is best to plan the structure of the aquaculture pond in detail with the existing land area. If the area is too large, the effect is not good in drug treatment.

2. Watergate and drain pipe:

The sluice is made of cement and brick, and the foundation should be stable to prevent it from being washed away. The inside and outside of the water gate are surrounded by thick and thin nets to prevent miscellaneous fish and shrimp from entering. The drainage pipe should be surrounded by fine nets in the larval stage to prevent shrimps from escaping. The position of the water gate and the drainage pipe should be opposite, and the included angle between the connecting line and the pond shore is about 35 degrees, so as to cause water flow and eliminate sundries and dirt.

3. Pool depth:

The depth of the pool should be above 1.5m, the water level should be above 3 feet at ordinary times, and the highest water level should be above 5 feet. In case of heavy rain, the overflow pipe should be preset at a height of more than 3 feet to prevent the sudden drop of salinity. The foundation of the earth embankment needs to be stable, and it is mainly soil. It is also better to spread a black net or enclose it with cement, and the slope is about 1: 1.5.

4. Bottom of swimming pool:

To level, tilt to the water outlet, it is best to spread sand or semi-sand on the bottom and compact. When the temperature of hot water exceeds 35℃ in summer, a ditch with a width of 5 feet and a depth of 1 foot can be dug around the bottom of the pond for shrimps to escape the heat.

5. Waterwheel:

Generally, each plot is equipped with about one waterwheel. In large-scale aquaculture ponds, the usage of 1/5 grade waterwheels can be reduced due to heavy wind and waves. The layout of waterwheel needs to consider the relationship between the shape of aquaculture pond, sluice, drainage ditch, seasonal wind direction and the speed of waterwheel. Generally speaking, a waterwheel can maintain the dissolved oxygen demand of 30,000 to 40,000 grass shrimps.

6. Conclusion:

The design of aquaculture pond needs to consider the overall cooperation, such as structure, waterwheel, sunshine, wind direction, inlet and outlet, and the design combination of the whole pond. The digging, stocking and future harvest need to be planned reasonably according to the actual needs, which is convenient for operation.

Fourth, the preparation work before releasing shrimp seedlings

1. Layout of aquaculture ponds:

The soil at the bottom of the old pond where grass shrimps have been stocked and the old pond where mandarin fish plague has been corrected is acidic. It is necessary to clean up the old soil and thoroughly disinfect it, and it is best to spread new soil. Before deciding the amount of quicklime, calculate the pH value of the soil. If the new pond has just been built, the amount of quicklime should be reduced or eliminated.

2. Water injection and disinfection:

The new pond needs to be filled with water and drained more than twice. After soaking, the algae should be cultured, the water quality changes should be observed, and the design of the culture pond should be examined for defects. The soaking time should be at least 15 days. Fill the old pond with water about 1 ft deep, disinfect it with drugs for about 2 days, and then drain it. After a few days of exposure, inject new water. At this time, tea cake water or lime water can be used to treat water quality, cultivate algae and adjust pH value.

3. Fertilization:

Fertilization in aquaculture ponds should be adjusted according to the water color after water inflow. Generally, it is hydrated lime, zeolite powder, etc. Should be used in accordance with the principle of a small number of times. Observe the change of water color first, and don't put too much fertilizer at one time.

4. Color of water:

Generally, it is better to cultivate stable green algae water or brown water containing diatoms to facilitate the growth of shrimp seedlings.

5. Salinity:

The stocking amount of shrimp seedlings should not be too different from the salinity of shrimp seedling farm, and it is better to be above 25 0/00. If the source of salt water is not easy, please ask the shrimp fry farm to desalt and domesticate the shrimp fry to a salinity suitable for the farm in advance.

6.pH value (acid salinity):

The pH value of the farm and shrimp farm should not be too different. If the pH value changes suddenly, the survival rate of shrimp seedlings will decrease due to insufficient adaptability, so it is best to adjust the pH value to no more than 9.

7. Water depth:

The water depth of the aquaculture pond should be injected about 2 feet first, which is not only convenient for observing the growth of shrimp seedlings, but also convenient for adjusting the changes of salinity, water temperature and pH value.

8. Drugs:

Do not use drugs indiscriminately after injecting water and cultivating water color one week before releasing shrimp seedlings. Zeolite powder and enzyme microbial preparation can be used to thoroughly decompose impurities and suspended solids at the bottom of the pond, remove NO2- and NH3 from the raw water of the aquaculture pond, and keep the water quality and color stable.

5. Selection and stocking of healthy shrimps.

1. Avoid unevenness:

The origin, place and time of shrimp seedlings in black shell farm and red tendon farm are different, which is more common in black shell farm. After the shrimp larvae are stocked, there will be individual differences due to different health conditions and adaptability. Although shrimp seedlings of the same size can be bought back after screening, they are easy to get hurt and suffer serious losses. So it's best to buy the same batch of shrimp seedlings.

2. Don't get foot disease:

Ciliated bacteria are attached to the bristles of swimming feet and tails, which can be observed and recognized by naked eyes.

3. The first pair of antennas:

The two tentacles of healthy black shell shrimp seedlings are close together. When the two tentacles are separated, they are closed immediately. If you can't turn it off, your health will be poor.

4. Abdominal part:

Those with long abdominal segments will grow better in the future, and those with short abdominal segments will grow worse in the future.

5. Rear fan:

When the shrimp fry swim, the tail fan will open, and the greater the opening, the healthier it will be.

6. Sticking behavior:

When the shrimps are scooped up with a white ladle, they will quickly swim to the ladle wall, and the people attached to the ladle wall are healthy. Swimmers are in poor health.

7. Gas temperature:

Pay attention to the weather forecast before stocking, and avoid raising shrimp seedlings before the cold current strikes. Pay attention to the water temperature adjustment if the shrimp fry unfortunately encounter a cold current after stocking.

8. Shrimp fry transportation:

It is best to choose early morning. If the time is prolonged, there should be shielding equipment to avoid direct sunlight. Fasting 12 hours before transportation, so as to avoid excreta polluting the water quality. It is best to fill the bag with seawater after two days of exposure, and avoid bumping during transportation. 3 ppm of methyl blue or 2 ppm of sulfanilamide preparation can be added to the water in the bag.

9. Stocking density:

If there is a shrimp storage pond, the shrimp can be stored for a period of time, and then moved into the culture pond according to its growth and survival. Generally, 300,000-400,000 red striped seedlings can be stocked in each plot in the water storage tank. If it is directly put into the cultivation pond, about 500,000 red striped seedlings (calculated by 50-60% of the live seedlings) and about 300,000 black-shelled seedlings (calculated by 70-80% of the live seedlings) can be raised in each plot. If the conditions of the aquaculture pond are particularly good and the water source is excellent, it is necessary to reduce the stocking density. The stocking density is related to the control of feeding amount, the pollution of bottom material and the stability of water quality in the future breeding stage, so we must consider our own breeding technology and the innate conditions of the breeding pond in detail. Do not blindly increase the number of aquaculture, resulting in future management problems.

10. Feeding:

After the shrimp larvae are stocked, they can be fed with 1 ~ 2 meals at a time, and artificial feed should be domesticated when feeding fish or mussels. To control the feeding amount, always check the bottom of the pool or the umbrella net to observe the feeding situation.

Six, the management of shrimp seedlings after release

Pay attention to the changes of water temperature, salinity, pH and water color at any time after shrimp larvae are stocked. After stocking, the sudden drop of water temperature should be avoided, and the change of salinity should be adjusted slowly. It is better to change water in and out at the same time, rather than changing water in large quantities. Grass shrimp hulls quickly and grows faster in the juvenile stage. As long as the feed is properly controlled, organic matter will accumulate, and NO2- and NH3 should be few. Changing water too much can easily make the osmotic pressure of young shrimp lose regulation, causing urgency of urination and physiological dysfunction. The control of water color in shrimp seedling stage should avoid high transparency, generally between 25-30cm. It is difficult to control the color of water that is too thick. If a large number of algae die, the dissolved oxygen will drop sharply. Even release harmful substances; The water color is too light, algae can't form advantages and reproduce in the water, shrimp seedlings can't absorb nutrients from algae, the shelling effect of shrimp seedlings is not good, and the concealment is low. Therefore, the control of water color in shrimp seedling stage should be based on the principle of stability, and the water color often changes. Shrimp seedlings are prone to physiological obstacles to adapt to the environment, which is one of the reasons for the formation of sky color.

Seven, the development stage of management

The growth of grass shrimp is slow, and the water quality changes due to external factors such as weather change, increased feeding amount and organic matter accumulation. Therefore, the management of aquaculture stage can also be said to be the management of water quality. In particular, when the grass shrimp enters 30/kg, the natural shelling speed slows down and the growth is slow. At this time, in addition to correct feed control, it is necessary to adopt different water changing methods and drug control according to the conditions of aquaculture ponds and different stocking densities. The control of bait needs to be calculated and increased according to the mantissa, weight, shelling rate and remaining bait quantity of shrimp in the pond. Generally, an umbrella net is placed in the shrimp pond, and then the eating time is observed regularly, and then the amount of bait is increased or decreased. In terms of water color control, the transparency of entering the adult stage is maintained at about 40cm, depending on the depth of the pond. If the algae are too thin in the shrimp seedling and adult stage, it is necessary to topdressing. The frequency, quantity and time of water change depend on the health of shrimp, the speed of algae reproduction and the accumulation of organic matter at the bottom of the pond. The ratio of salty fresh water to raw water in the aquaculture pond should not change too much. Although changing water at night can promote a large number of hulls, it is also easy to cause peeling and thin shells. Therefore, it is essential to replenish calcium and phosphorus in aquaculture ponds with frequent water changes. Drug treatment must be carried out according to the water source, pH value, sediment, shrimp disease status, drug characteristics, use time, etc. of the aquaculture pond to avoid drug damage, secondary infection of microorganisms and bacteria and heavy metal residue at the bottom of the pond.

Eight, the elements of water quality management

In order to understand the quality of water and control the color of water, we can discuss the following basic elements one by one. Generally, water quality can be detected and analyzed by instruments, and professionals and research institutions can also be entrusted for detection. Usually, farmers should actually observe and understand the changes of air temperature, water temperature, salinity, pH value and water color, and it is best to make records.

1. Salinity:

Grass shrimp can be reared in euryhaline from 300/00 to 400/00, with the best stage above 25 0/00, and then slowly diluted during the breeding period, and the adult stage is best maintained at 100/00 ~ 200/00. Although the lighter shrimp pond grows rapidly, it is not easy to deal with this disease because it quickly hulls calcium salts in feed. The culture pond with high salinity has a long culture cycle, so the number of water changes should be increased to promote shelling. After the date of selling shrimp is determined, it is best not to change the water, especially within 3 days, so as to avoid shelling. In a lighter culture pond, the salinity can be gradually increased 15 days before the shrimp is expected to be sold in the pond, so as to reduce the amount of shelling and increase the thickness of shrimp shells. Salinity can be measured by hydrometer or baume meter.

2. Water temperature:

The suitable temperature range of grass shrimp is between 20℃ and 32℃, but between 27℃ and 30℃. The temperature of pond water can be adjusted by the depth of aquaculture pond, the change of water and the number of waterwheels. In winter, the temperature difference between day and night is large, so underground well water can be extracted to adjust the water temperature in areas with groundwater. The layout of waterwheels, the position of import and export and the control of algae should be arranged reasonably to avoid temperature stratification. To measure the temperature with a water thermometer, it is best to record the temperature at different depths.

3.pH value:

The determination of pH value can be used as an index of pond water quality. The adaptation of grass shrimp to pH value is between 7.5 and 9.2, that of young shrimp is between 8.0 and 9.2, and that of middle shrimp is between 7.5 and 8.8. The pH value increases with the consumption of carbon trioxide by algae in photosynthesis. If there are too many algae, it will hurt the gills of grass shrimp, and the pH value will be reduced due to the corruption of algae, aquatic organisms and organic matter. If the pH value is too low, it will reduce the oxygen transport function of grass shrimp and form respiratory disorder. Therefore, we should always pay attention to how to adjust the pH value to the most suitable range of grass shrimp, that is, the control of algae reproduction, the removal of organic matter and the observation of water color. When the pH value is too low, try to eliminate organic matter, change water and add quicklime water to adjust; When the pH value is too high, the algae content in the culture pond should be adjusted or reduced by changing water. What must be mentioned is the use of alum. Farmers seem keen on using alum. The dead hyphomycetes and feet of grass shrimp were treated with alum near the shore. In fact, the pH value of alum is too high, which can be used to reduce and adjust the color of water. When the pH value is not too high, it will cause a sharp drop in pH value and a large number of grass shrimps will die. The test of PH value is generally determined by pH meter, pH test paper and pH titration solution. The pH value is the highest at 4 pm and the lowest at 4 am every day. It can usually be measured and compared at 10 am and 4 am.

4. Dissolved oxygen:

The level of dissolved oxygen directly affects the yield of grass shrimp per unit area. Dissolved oxygen in the water not only maintains the consumption of grass shrimp, algae and aquatic organisms, but also supplies the consumption of chemical oxygen demand of organic matter at the bottom of the pond. The source of dissolved oxygen is generally obtained by pumping air from waterwheels, entering and leaving water during the day and photosynthesis of algae. If dissolved oxygen is sufficient, shrimp manure and residual bait can be decomposed into nutrients of algae by aerobic bacteria, but if algae are too dense, photosynthesis cannot be completely carried out due to insufficient sunlight at the bottom. The oxygen consumption below the middle layer is more than the output, and the upper layer is too saturated, which is easy to dissipate into the atmosphere, causing temperature stratification and floating shrimp. Moreover, in aquaculture ponds with high salinity, due to insufficient dissolved oxygen, sulfate ions are easily reduced to hydrogen sulfide, which is toxic. When using medicine, whether the purpose is to kill exotic algae or decompose organic matter at the bottom of the pond, or even to change the environment of the aquaculture pond and stimulate shrimp to shell, we should pay attention to the full pumping of the water wheel to avoid insufficient dissolved oxygen. In addition, farmers generally use potassium permanganate (red medicine) for first aid when grass shrimp floats, but it also often causes phytotoxicity. When using this medicine, we must pay attention to the dosage, the use time, the change of pH value and the accumulation of organic matter at the bottom of the pool. The redox degree can be determined by hydrometer or titration.

5. Transparency:

In other words, the control of water color, the index of algae growth density, and the transparency of grass shrimp pond should generally be kept above 30 ~ 40 cm, depending on the depth of the pond. Transparency is generally defined as the depth at which the white dish hangs into the culture pond until the dish is out of sight, and the compensation depth is twice as much as transparency. At the compensation depth, photosynthesis can be completely carried out. Below the compensation depth, due to insufficient sunshine, anaerobic bacteria grow, causing the fermentation and reduction of organic matter, forming sulfide and hydrogen sulfide. Grass shrimp prefer to live in a highly private environment. In order to control algae, it is necessary to adjust the existing conditions of aquaculture ponds.

6. Ammonia:

Organic matters such as feed residue and shrimp excrement exist in two forms after decomposition: undissociated ammonia (NH3) and dissociated ammonia (NH4+). NH3 is highly toxic and NH4+ is less toxic. When the water in the aquaculture pond is too high and the pH value rises, the proportion of NH3 will increase, so the toxicity will be enhanced. If the dissolved oxygen is insufficient, ammonia will be more toxic and more harmful to prawns. Therefore, it is very important to change water and pump water when the temperature is high in summer. Aquaculturists usually call ammonia "ammonia" or "ammonia". Generally, when the concentration of ammonia (that is, the sum of NH3 and NH4+) exceeds 1ppm, cultured shrimp will be poisoned, and when it exceeds 5ppm, grass shrimp will die in large numbers, which is usually determined by ammonia (NH4+, ammonia) test solution.

7. Nitrite:

Ammonia is decomposed into nitrate by nitrifying bacteria in water, which becomes the nutrient salt of algae and aquatic plants. But when oxygen is insufficient, anaerobic bacteria convert it into highly toxic nitrite. When the content of nitrite in water increases, the oxygen transmission function in the blood of grass shrimp will decrease. Even if there is enough dissolved oxygen in the culture pond, grass shrimp will float on the water surface and become sick, swimming around or near the shallow water shore. The safe concentration of nitrite in aquaculture ponds should be below 0.5ppm, and the appropriate water color and transparency should be adjusted, or nitrite should be decomposed by photosynthetic bacteria and determined by nitrite determination solution.

8. Hydrogen sulfide:

When protein in feed, such as protein and raw bait, remains at the bottom of the pond, it is first decomposed into hydrogen sulfide in an oxygen-enriched culture pond, and then oxidized into nontoxic sulfate by aerobic bacteria. However, when the dissolved oxygen in the bottom layer is insufficient, the oxidation process stops and highly toxic hydrogen sulfide is produced. Usually, iron ions in the water will combine with sulfur to form iron sulfide, and the sludge in the pond will turn black, producing malodorous gas, which is usually lower than pH value, with low dissolved oxygen and high water temperature. Therefore, it is easier to change. When the concentration of hydrogen sulfide reaches 0. 1ppm, prawns are harmful and can be determined by hydrogen sulfide meter.

9. Heavy metal content:

If the iron content in the water source of the aquaculture pond is too high, the gill respiration of prawns is harmful. It is better to have a reservoir. When aquatic drugs containing copper and manganese are used to treat the diseased water quality in aquaculture ponds, attention should be paid to the dosage, and the water should be changed to avoid residue and accumulation.

10. Various water color analysis:

1. reddish brown water:

Mainly the result of a large number of diatoms. In the early stage of culture, it is easier to produce diatom water color because of feeding raw fish pulp to shrimp fry, which is most suitable for shrimp fry culture. Unfortunately, careless management is easy to pour water, and shrimp farmers have changed their water color.

2. Green water:

The culture pond contains a lot of green algae, and the water color is relatively stable and easy to maintain. Even if it turns strong green, grass shrimp is unlikely to get sick and die. If the water color can be properly managed and the green components can be moderately shaded, the grass shrimp will be bright and yellow-green.

3. Dark green water:

As the water temperature rises, the organic matter accumulates into blue-green algae, and the green algae decreases. The more blue-green algae there are, the darker the water is. In this water color, shrimp grows slowly, which will cause many phenomena of different sizes. If salinity is low, it will turn into sky color.

4. Black water:

Too much feed, too much organic acid and humic acid in the sediment, and a large increase in soluble and suspended organic matter, resulting in poor transparency. If oxygen is insufficient, grass shrimp can easily get soft shells, black cheeks and red cheeks, and must be treated with water.

5. White turbid water:

Most of them are composed of zooplankton, such as cilia or wheels. As a result of mass reproduction, the dissolved oxygen in the culture pond is reduced, resulting in anoxia, and protozoa such as cilia attack grass shrimp in poor health or just shelled. These grass shrimps are easy to get sick and die.

6. Yellow muddy water:

Most of them occur in green water aquaculture ponds. Because the clay on the shore is dissolved in the hydroponic pond, the content is high and it cannot be precipitated. Because it can combine nutrients, organic matter, microorganisms and algae to become cotton flocs and feed for grass shrimp. Although yellow mud water can stabilize the growth of shrimp, it should not be too long and the content should not be too much. It is best to change the water.

7. Clear water:

In the newly-built pond, due to the leakage of the culture pond, the soil is too acidic, the water quality is transparent, green algae and large aquatic plants are easy to produce, the shrimp in the pond are difficult to grow, and the dissolved oxygen is insufficient. Top dressing should be carried out and the bottom of the seepage pool should be filled up.

8. Rusty water:

Too much iron in the underground water source will turn the bottom of the pool red, so use a reservoir. The bottom of the pool with too much copper will turn blue-green, and the bottom with too much manganese will turn black, so pay attention to the residue problem when using drugs.

9. Luminous water:

During the day, no abnormality can be detected in the water in the pond. At night, when there is no light, you can see the fluctuation of water, such as the splash from the waterwheel, the fluctuation caused by shrimp swimming near the wall of the pond or near the water surface, which shows fluorescence, and even a large number of shrimp attach to make the whole body glow. At night, a large number of dead residues accumulate at the bottom of the pond to produce toxins, which will reduce the consumption of shrimp. It can be treated with quaternary ammonium disinfectant, malachite green, copper sulfate and tea cake, and a lot of water can be changed.

Nine, the main points of water quality management

1. Air exposure:

It is best for the groundwater extractor to pass through the multi-stage steps or aeration of the high water tower, and then enter the ditch. You can also use a circulating filter tank, and the reservoir will be pumped or flowed into the aquaculture tank.

2. Change water:

Changing water is the most important work in the breeding period. To maintain a good water color, we must master the essentials of changing water time, quantity and method. After the shrimp larvae were stocked, a small amount of water was drained and fed, and the water level in each growth stage gradually increased. Young shrimps use the principle of changing water after, which is the same inside and outside. After prawns, water can be changed as appropriate. In aquaculture areas where seawater tidal range is used to change water, it is necessary to know the time of high tide and low tide of seawater. Farmers generally change water from dusk until around 1 1 p.m. Although a large amount of water collection at night can promote shelling, it should not be frequent, and the water change work in the late stage of high salinity aquaculture pond must be frequent. When changing water, the operator should observe the color of water before deciding the time of changing water. In the middle stage of culture, the weekly water exchange rate of shrimp ponds with low salinity (100/00 ~ 160/00) should be above 15%, and the weekly water exchange rate of areas with salinity above 20 0/00 should be above 25%. In addition, before the typhoon strikes, when the air pressure is low, in hot summer and before the northwest rain comes, water must be injected. When the rainy season comes, to maintain the salinity of water quality, it is best to add an upper drainage pipe to the aquaculture pond.

3. Introducing algae water;

Improper water quality management, bad weather, and even bad sediment will cause the color of water to become thicker and a large number of algae will die. Change the water as soon as possible and introduce algae seeds to cultivate the water color.

4. Waterwheel:

Although there is no need to use a waterwheel in shrimp seedling stage, it is best to get in and out of water in small quantities at about 5 am every day, and it is best to start the waterwheel to pump water in large-scale aquaculture ponds. In summer, when the temperature is high during the day, it is best not to stop the waterwheel. In addition to increasing dissolved oxygen, the waterwheel can disperse excess oxygen in the water into the atmosphere, at the same time, supplement carbon dioxide to accelerate photosynthesis, destroy the temperature, form water flow, make the water temperature consistent, and distribute plant plankton evenly in the whole culture pond.

5. Drug use:

Tetramine disinfectant, including copper preparation, malachite green, methyl blue, tea residue, etc. Can disinfect the culture pond and control the growth of algae. It must be noted that excessive use should not kill algae, or even cause secondary infection of residual poison, bacteria and microorganisms. If the pH value is found to decrease, lime water should be added as appropriate to adjust it.

6. Improve sediments and water quality;

Lime, 1 fertilizer, urea and zeolite powder can be used as nutrients in new ponds or aquaculture ponds with unsatisfactory water color. For aquaculture ponds with low salinity, crude salt can be used to increase salinity, especially in the estuary area where salt water is easy to get when the rainy season comes. Enzymes, microorganisms and preparations can be used to decompose nitrous acid, and zeolite powder can absorb hydrogen sulfide and ammonia at the bottom of the pond. However, different systems of zeolite powder, rocks and soil are different, so it is necessary to understand the product characteristics. Take products suitable for aquaculture ponds.