Aquaculture | water change law of shrimp pond to improve the survival rate of shrimp

To raise shrimp, you must raise water first. In the whole process of raising shrimp, water quality regulation is very important. Adding and changing water is one of the simplest ways to regulate water quality. Should the shrimp pond change water? Some people say that prawns are very fragile. Changing spines to stimulate prawns to shell frequently weakens their physique and is prone to disease. Others say it’s impossible not to change the water. After a long time of raising, the water quality is eutrophic, so we have to change the water. Should I change the water in the process of raising shrimp? Or under what circumstances can the water be changed and under what circumstances cannot the water be changed?

Five conditions shall be met for reasonable water change

1. Prawns are not in the peak period of shelling, and their physique is weak at this stage to avoid severe stress;

2. Prawns have healthy physique, good vitality, vigorous feeding and no disease;

3. The water source is guaranteed, the offshore water quality conditions are good, the physical and chemical indexes are normal, and there is little difference from the salinity and water temperature in the shrimp pond;

4. The water body of the original pond has a certain fertility, and the algae are relatively vigorous;

5. The inlet water is filtered with a dense mesh to strictly prevent wild miscellaneous fish and enemies from entering the shrimp pond.

How to drain and change water scientifically in each stage

1) Early breeding stage. Generally, only water is added without drainage, which can improve the water temperature in the shortest time and cultivate sufficient bait organisms and beneficial algae.

When adding water, it can be filtered with two layers of screens, with 60 mesh for the inner layer and 80 mesh for the outer layer, so as to prevent enemy organisms and fish eggs from entering the shrimp pond. Add water for 3-5cm every day. After 20-30 days, the water depth can gradually reach 1.2-1.5m from the initial 50-60cm.

2) Medium term breeding. Generally speaking, when the water volume exceeds 10cm, it is not suitable to change the filter screen to remove impurities every day.

3) Later stage of breeding. In order to increase the dissolved oxygen in the bottom layer, the pool water should be controlled at 1.2m. However, in September, the water temperature began to drop gradually, and the water depth can be increased appropriately to keep the water temperature constant, but the daily water change shall not exceed 10cm.

By adding and changing water, we can adjust the salinity and nutrient content of water in shrimp pond, control the density of unicellular algae, adjust the transparency, and increase the dissolved oxygen content of water in shrimp pond. In the high temperature period, changing water can cool down. By adding and changing water, the pH of water in shrimp pond can be stabilized and the content of toxic substances such as hydrogen sulfide and ammonia nitrogen can be reduced, so as to provide a good living environment for the growth of shrimp.