What conditions are needed for shrimp farming, and how is quicklime used?
In recent years, the market demand for crayfish has gradually increased, and as a snack food it is increasingly favored by consumers. Many people have seen the prospects of crayfish farming, and its farming profits are also very considerable. Although crayfish have a very strong ability to adapt to the environment, the farming industry still requires certain farming techniques.
What conditions are needed for shrimp farming
1. Water quality
It directly affects the healthy growth and development of crayfish. During the farming process, the pH value of the pond water should be kept between 7.5-8.5, and the transparency should be 30cm-40cm. New water should be added frequently, and quicklime solution should be sprinkled regularly to regulate water quality and prevent disease outbreaks and incomplete molting, etc.
2. Reasonable feeding
When crayfish are hungry and food is insufficient, they will cannibalize each other, so the feeding amount must be sufficient. Crayfish feed consists of animal and plant feed. Plant feed includes wheat, aquatic plants, rapeseed cake, etc., while animal feed includes miscellaneous fish, miscellaneous meat, and livestock internal organs, etc. Usually, according to the crayfish's habit of hiding by day and coming out at night and the density of shrimp in the pond, determine the feeding time, feeding amount, and feeding method. Otherwise, it will increase feed costs and reduce farming benefits.
3. Scientific harvesting
During the crayfish farming process, when the temperature is suitable and feed is sufficient, juvenile shrimp can generally grow to commercial size in 60 days-90 days. Stock fry in March, and begin rotational harvesting around June, catching the large ones and leaving the small ones. Because of catching the large and leaving the small, and rotational catching and stocking, the recapture rate can be increased, a good price can be obtained, and the goal of high yield and high efficiency can be achieved.
How to use quicklime in shrimp farming
1. Application of quicklime in pond clearing
Quicklime releases a large amount of heat when it meets water and generates calcium hydroxide, which is strongly alkaline, causing the pH value of the pond water to rise sharply and quickly killing bacteria, parasite eggs, aquatic insects, harmful fish, frog eggs, moss, and some aquatic plants, thereby achieving the purpose of eliminating diseases and pests.
2. Dry pond clearing
Generally, for ponds with sufficient water sources and relatively convenient drainage and irrigation, dry pond clearing can be used. First drain the pond water or keep a water depth of 5-10 cm, and use 50-75 kg of quicklime per mu (if there is more silt, the amount of quicklime used can be appropriately increased). When clearing the pond, dig pits at the bottom around the pond or use containers such as wooden buckets, put quicklime in and add water to dissolve it, and immediately sprinkle it evenly around the entire pond before it cools. Raking the pond mud with a rake gives a better effect.
3. Clearing the pond with water
Generally, it is more suitable for ponds with insufficient water sources and less convenient drainage and irrigation. For clearing the pond with water, according to the amount of pond water, generally use 0.2 kg of quicklime per cubic meter of water. Usually, put quicklime into a wooden bucket or water vat, dissolve it, and immediately sprinkle it over the entire pond, while also sprinkling the pond edges. Fry can be stocked only after the medicinal effect disappears after 7-8 days.
Preparation for stocking crayfish
1. Thoroughly clear the pond: 20-30 days before stocking shrimp fry and shrimp seed, drain the pond water, remove excess silt, repair the pond banks, and use 75 kg of quicklime per mu or drugs such as bleaching powder and bleaching powder concentrate to thoroughly clear the pond and disinfect it.
2. Apply sufficient base fertilizer: apply 500-600 kg of decomposed livestock and poultry manure per mu to cultivate rotifers and cladoceran and copepod plankton, providing palatable bait for shrimp fry and shrimp seed.
3. Plant aquatic plants well: plant aquatic plants such as Hydrilla verticillata, Potamogeton malaianus, and Elodea in the farming pond, covering 2/3 of the shrimp pond area. At the same time, set up netting, or place bamboo tubes, plastic tubes, etc., to provide habitat, molting, and hiding places for Procambarus clarkii.
Disinfection methods for crayfish farming ponds
1. Quicklime disinfection
Before using quicklime for disinfection, leave only 5-10 cm of standing water in the pond, break up the quicklime and sprinkle it evenly into the pond water to dissolve. The amount of quicklime used is generally 20-40 kg per mu. On the second day after using quicklime, use an iron rake to stir the pond bottom so that the lime slurry and silt are fully mixed.
2. Bleaching powder disinfection
Using bleaching powder to disinfect crayfish farming ponds requires draining the pond water. Use 0.5-1 kg of bleaching powder with an effective content of more than 30% per mu. For ponds that are not drained, use 1.5-2.5 kg of bleaching powder with a content of more than 30% per mu per 1 meter of water depth. When using, first put the bleaching powder into a wooden basin or iron bucket, add water to dilute it, and sprinkle it into the pond. Do not release the disinfected water; keep it in the pond. Start adding water the next day, and once the water level meets the rearing requirements, it is fine.
3. Caustic soda disinfection
At present, many crayfish farms commonly use caustic soda to disinfect ponds, but caustic soda does not act quickly, is ineffective against many viruses, is corrosive, and easily reacts with carbon dioxide and becomes ineffective.
That is all for now on crayfish farming techniques. I hope it is helpful to everyone. Crayfish have a very strong ability to adapt to the environment, so friends who have ideas and experience can still give it more consideration, especially since it can also achieve the advantage of two-way farming with rice fields.