Farming pond and location selection:
Pond has area of 1,000 square meters-2,000 square meters, water’s depth level from 1.5-2 meters.
Hatching pond should be located near canals, irrigation ditchs where it is easy for water supply and sewerage and care control. Do not plant big trees around the pond which will cover the sunlight and the leaves falling pollutes the water and environment.
Drain out of water; clean layer slop; fill spelaean of crabs, frogs, rats, eels; repair border; cut the grass surrounding the pond bank to prevent crop pests in the period of stocking fries.
The amount of powdered lime to scatter the pond is
10-15kg per 100 square meters of pond. After spreading the powdered lime, the pont must be deposited for 2-3 days.
Supply water into the pond and add nutrition into the water:
After water supply flows into the ponds by aqueduct, awueduct has barrier with wire netting to prevent eggs, waste fish, crustacean. Water supply need to be deposited in sedimentation pond from 5-7 days before flowing into the pond.
Supply the water into pond 1 day before stocking fries
In seed hatching, need to add the water with natural feed in the early stage for fish fries.
With pond area of 1,000 square meters: Manure 2 kg fishmeal contained 40 percent protein plus 2 kg flour soy-bean to feed fish with natural food.
Before discharging fish, check up factors of water environment to ensure:
- pH: 7-8
- Temperature: 28-300C
- Oxygen ≥ 3mg/litre
Seed and density:
Fish stocks need to be carefully selected to ensure the quality and growth rate of fish during the raising period. They are selected from credible hatcheries with high traceability of broodstock which can meet veterinary and hygiene conditions as required.
The selection of fish stocks:
- The fish looks healthy, with no signs of illness or scratches; misshapen fish are eliminated. Observations in fish holding tools shown that fish move fast, near out of citellus, bright colour.
- The fish size must be equal.
- The most suitable time for stocking fries is in the early morning and the late afternoon.
- Density: 500 individuals/square meter.
Feed and Diet of feed: The following instructions are served for 1 million fries.
v The first week:
- Feed mixture for 1 time feeding
+ flour soy bean: 300g
+ flour milk: 300g
- Frequency of feeding: 5 times/day at 7h, 10h, 14h, 17h, 20h.
- Way to feed: dissolve the mixture and disperse the whole surface of pond,
v The second week:
- Feed 5 times per day at 7h, 10h, 14h, 17h, 20h. Feed is industrial feed flour with 40 percent of protein. Dosage: 0.5kg for 1 time feeding (5 times a day equal to 2.5 kg per 1 million fries a day).
Gradually increase the 20 percent amount of feed each day (depend on fish’s feed consuming ability).
- Way to feed: disolve the mixture with water and scatter the whole surface of pond.
v The third week:
Use industrial feed with the protein of 35-40 percent.
Times for feeding: 4 times per day (8h, 1h, 14h, 17h).
Gathering fish and feeding at one position to determine the suitable amount of feed.
v From the fourth week and later:
Use floating industrial feed with protein content 30-35 percent and suit with fish’s mouth.
Fish is fed 3 times a day. Fish must be fed with feed that is full of quantity and quality.
In the end of fourth week, to start classifying fish to distribute them in pond with density of 150-200 pecies/square meter.
Control and care:
- Prevent pests (snake, eel, waste fish, harmful fish) to penetrate into hatching pond.
- Observe the water colour in the ponds which must be between green and yellowish.
- When feeding fish, ensure 4 factors “quantity, quality, place, and time to help fish grow well and limit pollution at hatching pond.
- Periodically use some bioproducts to clean the water such as EM, Zeofish,...
- After the first rains of the rain season, use dissolved lime (settle down), about 20-30kg/1000 square meter to spread the whole surface of the pond.
- Use vitamin C regularly to raise resistance for fish
- Fish seed for commercial farming must ensure traceability and meet requirements of Ministry of Agriculture and Rural Development (MARD), must have quarantine certificate from relevant agencies. Breeding season: obey each locality’s yearly harvest crop schedule.