How to Farm Tilapia? A Detailed Explanation of Key Tilapia Farming Techniques
Currently, China is already the world's largest country in the use of tilapia farming techniques, and tilapia has become one of the leading aquatic products in China's main aquaculture export output. So what are the key points of tilapia farming techniques?
I. Pond Preparation
1. Site Selection
The surroundings of the pond must be kept free of pollution sources, with convenient water and electricity supply and convenient transportation. Good water quality and ample sunlight are required, and it must not be located next to tall buildings. The pond should have convenient water intake and drainage, and the pond bottom should be flat and free of debris, with an area of 0.37-0.54 hm2 being suitable; ponds with a mud bottom or sandy-mud substrate are best. Keep the water depth uniform, generally 1.8-2.5 m. To prevent oxygen deficiency, it is recommended to equip a 3 kW three-phase impeller aerator.
2. Disinfection
In addition, the pond must be disinfected before stocking. The main methods of pond clearing and disinfection are dry pond clearing and clearing with water.
(1) Dry pond clearing
First drain the water from the pond or leave 5-10 cm, then dig small pits in the pond bottom or use a wooden bucket, put in 50-75 kg of quicklime and dissolve it with water, and immediately sprinkle it evenly around the pond bottom, also sprinkling the base of the embankment; finally use a rake to move the pond mud for disinfection.
(2) Clearing with water
10 d before the fry are stocked into the pond, use 250 kg of quicklime with 10-20 cm of water and sprinkle it over the whole pond for disinfection; likewise, dissolve the quicklime in a wooden bucket and immediately sprinkle it over the whole pond.
II. Water Quality Cultivation
10 d after pond clearing, fill the pond with about 1.0 m of water, and during filling strictly filter it through 60-80 mesh silk gauze, keeping the water depth at 80-100 c. After pond clearing and disinfection, apply 300-500 kg of decomposed manure to maintain good water quality, thereby cultivating an appropriate amount of phytoplankton and zooplankton. Choose a sunny midday to fertilize and cultivate the water, promoting the reproduction of plankton and increasing the pond's basic yield and self-purification capacity.
III. Stocking of Fry
1. Selection of Fry
When stocking fingerlings, generally choose fingerlings with a total length of about 15 cm and a body weight of more than 100 g. Also choose certified tilapia fry, which have the characteristics of uniform size, robust physique, lively swimming and fast growth.
2. Stocking Time
Tilapia is a tropical fish, so the water temperature must not be lower than 18°C, and the temperature difference when the fry enter the pond should be less than 2°C. Stock the fingerlings only after the water temperature has stabilised and 10-15 d after pond clearing and disinfection, when the toxicity has disappeared and plankton have multiplied in large numbers. The optimal stocking density is 1600 fish/667 m2. Also match with a certain proportion of water-purifying fish, such as overwintering fish, bighead carp and silver carp.
IV. Daily Management
1. Feeding
The crude protein content of fingerling feed is required to reach 35%-40%. With green feed as a supplement, the green feed used is required to be free of accumulated pesticide residues. Keep the crushing fineness of feed ingredients at 40 mesh or above.
2. Aeration
Use a microporous aerator for aeration. In summer, insist on running the aerator every day, using the water-stirring effect of the aerator to increase dissolved oxygen in the water body, promote the decomposition of organic matter from bottom impurities, and prevent fish from gasping at the surface due to oxygen deficiency.