Regulation of water color in shrimp ponds in middle and late stages

(Agricultural Wealth Network) In the middle and later stages of Penaeus vannamei and Macrobrachium rosenbergii cultivation, a large amount of organic matter such as residual bait and feces sank to the bottom of the pond, especially a large amount of N element deposited at the bottom of the pond, resulting in the imbalance of N and P ratio in the pond, thus causing abnormal reproduction and growth of algae, resulting in various dangerous colors, which caused great harm to shrimp cultivation. The following are some common dangerous water colors in shrimp ponds in the middle and late stages, and some experience and methods for improving such water quality are provided for reference.

Dark green turbidity--blue-green or dark green

This kind of color is common in the middle and late stages of culture. Sometimes some floating substances will be produced on the surface of this color. There are a large number of suspended blue-green particles in the water body. The water surface is oily. The water quality is thick, turbid, sticky and slippery. The foam tail is difficult to disappear. This indicates that the concentration of harmful algae is large and begins to die. The surface of foam accumulation at the downwind has obvious dirt adhesion, accompanied by fishy smell, and the water played by the aerator is dark green or dark blue-green. The shrimp in this water quality is obviously reduced, the jejunum is empty, the vitality is weak, and the shrimp body is thin. If it is not properly improved in time, it will also lead to the disease harm mentioned above. Countermeasures: drain and change about 15cm of water, sprinkle detoxification stress essence on 3 mu of rice per bottle in the whole pool, cultivate with Bacillus species (2 jin brown sugar per vial) at about 9:00 a.m. after 1-2 days, use 5 mu of rice water for each vial, and then dry sprinkle with 6 mu of bottom water per bag after 2-3 days according to the color of water.

Sauce red, dark brown

This kind of water often contains a large number of harmful algae, such as dinoflagellates, gymnodinoflagellates, etc. The main reason is that the feed feeding is not scientific, the residual bait and feces increase in the middle and late stages, and the bottom is not changed in time, resulting in the increase of suspended organic matter in the water body, and the water quality is eutrophic, which makes the harmful algae form a dominant population and inhibits the growth of beneficial algae. These harmful algae secrete nerve-paralyzing toxins that can easily cause shrimp poisoning and death. This kind of water quality is turbid, dead, sticky and smelly, the foam tail is long and difficult to disappear, the foam surface accumulated at the downwind port has obvious dirt adhesion, and the water color played by the aerator is light dark red or dark red. Shrimp reduced feed obviously, jejunum empty stomach, vitality obviously weakened. If this water quality is not handled properly in time, it will definitely cause serious diseases, such as stealing death at the bottom, red body white spots, liver swelling and necrosis. Countermeasures: drain and change water for about 15- 20cm, sprinkle detoxification stress essence for 3 mu per bottle, dry sprinkle the whole pond with bottom clear water for 6 mu per bag on the second day, and mix 1 barrel of ecological fertilizer paste with 1 bag of green water No.1 according to 8 mu rice for 2 hours after soaking for 2 hours, and then sprinkle the whole pond.

Yellow mud color--muddy water color

This color is mainly due to the aging of the bottom of the pool, the content of harmful substances in the sediment exceeds the standard, the sediment loses its biological activity, and it is easy to be turbid when the weather changes, and the color is extremely difficult to adjust. Most farmers adopt polyaluminum chloride, aluminum potassium sulfate and other physical water purification agent treatment, this method can not fundamentally solve the phenomenon of turbid water, but also easy to rebound. The treatment of muddy water quality should be treated gradually: (1) drain and change about 15cm of water, activate the substrate with bottom quick-release ammonium sulfate, and sprinkle with 6 mu of rice per bag of bottom clear water on the next day;(2) mix and sprinkle ecological fertilizer paste with Bacillus strain culture solution;(3) after culture, soak for 2 hours with water-retaining rishengsu and green water No.1, sprinkle the whole pond to stabilize algae phase.