CATDOLL : CATDOLL: What are the requirements for water quality management in pond shrimp farming?

Strengthening the management of shrimp pond water quality and creating a good ecological environment are important measures to achieve high yields of shrimp farming in ponds. Specifically, the following four aspects should be mastered:

(1) Manage the water quality of shrimp ponds in accordance with the requirements of water environment conditions for the growth and development of freshwater shrimps. Freshwater shrimps are crustaceans, and require the dissolved oxygen in the pond water to be above 5 mg/L, the pH to be 7-8, the water transparency to be around 40 cm, the silt at the bottom of the pond to be around 10 cm, the organic matter content to be low, and the water quality to be fresh and lively. During the shrimp farming process, strengthen the monitoring and regulation of water quality, maintain good water quality, and promote the growth of freshwater shrimps.

(2) Manage the water quality of shrimp ponds according to the changing rules of the main water quality factors. Dissolved oxygen is an important factor in water quality. The main sources of dissolved oxygen in water are: first, photosynthesis of green plants; second, dissolving oxygen in the air into water through wind diffusion; third, supplementing oxygen in water through artificial measures. The consumption of dissolved oxygen in water is: first, oxygen consumption by aquatic organisms; second, wind diffusion, which returns dissolved oxygen in water to the air; third, oxygen consumption by the decomposition of organic matter in the pond. The diurnal variation of dissolved oxygen in water is: in clear weather, due to the photosynthesis of green plants, a large amount of oxygen is released, and the dissolved oxygen in water reaches saturation around noon. At night, the photosynthesis of green plants stops, aquatic organisms consume a lot of oxygen by breathing, and organic matter decomposes and consumes oxygen. The dissolved oxygen in the shrimp pond is at the lowest level before dawn. Therefore, it is easy to cause hypoxia in shrimp at night and early morning. In addition, the water quality of shrimp ponds can also cause hypoxia through irregular fertilization, the death of a large number of algae, or continuous rainy weather. Pond inspections should be strengthened, attention should be paid to the changes in water quality and dissolved oxygen, and oxygenation measures should be taken in time to avoid hypoxia accidents and losses. The pH change of shrimp ponds is mainly caused by the metabolites of anaerobic bacteria and the organic acids produced by the decay of leftover bait. In addition, factors such as acid rain can also cause changes in the pH of pond water. The transparency of shrimp pond water is mainly determined by the amount of suspended matter in the water, especially the amount of algae. Usually, tea brown and oily green are better, and the transparency is about 40 cm. Water quality management should be strengthened according to the day and night changes of these factors.

(3) Manage the water quality of the shrimp pond according to the seasonal changes in fishing seasons. In the early stage of shrimp fry stocking, the water depth of the shrimp pond can be maintained at about 0.8 meters. August to September is both a hot weather and the peak season for the growth of freshwater shrimp, so the pond water should be filled to a depth of 1.2 to 1.5 meters. The water quality in autumn is very easy to change. Depending on the water quality of the shrimp pond, water should be added or changed once every 7 to 10 days. The amount of water changed should not be too large, generally about 1/4. Or start the aerator regularly to add oxygen to the shrimp pond. In normal times, if the water quality is found to be too rich or too concentrated, water should be added or changed in time to regulate the water quality.

(4) Manage the water quality of the shrimp pond according to weather changes. Keep listening to weather forecasts and patrol the pond in the morning and evening to observe changes in the water quality of the shrimp pond. Take appropriate measures based on the weather, water quality and shrimp activity to maintain good water quality.

This article is from: China Agriculture Press "Green Development and Green Plant Protection"