In terms of value, shrimp is the most important commodity in international seafood trade. In the past few decades, the shrimp industry has doubled and is expected to continue to grow in the next few years.
Many enterprising shrimp farmers are now using a new and better technology to breed shrimp. Green water technology is a technology that cultivates shrimp in water rich in phytoplankton, namely chlorella, to make the water green, hence the name.
When preparing the pond, dry the pond for three weeks and drain the water until the soil at the bottom of the pond cracks. The silt or black soil at the bottom of the pond should be scraped off. Then fill the pond with water and dry it for another week. Before final washing and drying, hydrated lime is applied at a rate of 2 tons per hectare.
When the pond is clean and dry, a double-layer Harpa net (10×10×1.5 m) should be installed in the center of the pond. From the dam to the fence, a bamboo flyover should be set up to facilitate feeding and monitoring of fish schools.
Water Culture/ Fertilization
After the pond is installed, the seawater should be poured into the pond to a maximum depth of 1.0-1.2 meters, and the gate should be sealed. A depth gauge should be installed to maintain the water depth. To ensure that there are no predators and other possible competitors in the water, theophylline powder (20ppm) should be applied. A fine mesh screen should be installed at each exit of the tank to prevent predators from entering the pond while pumping.
Stocking and Sampling
In order to check the growth and condition of shrimps, samples should be taken after 30 days of cultivation and every 10 days thereafter.
For shrimp, they should be fed immediately after stocking. The shrimp feed is broadcast around the pond, and a portion of the feed is kept in the feeding tray. Four feed pans with an area of 0.25 square meters should be set up to monitor feed consumption daily. In the first 30 days, blind feeding was carried out. Feed about 200 grams of feed for every 10,000 larvae. 1 to 3 hours after feeding, open the feed pan to estimate the amount of feed consumed. Starting from the 40th day of breeding, the shrimps were fed 5 times a day, that is, 6:00 am. 10:00 am, 2:00 pm, 5:00 pm, and 10:00 pm, which are respectively 20%, 10%, 10%, 35%, and 25% of the total feeding amount.
Water Management and Aeration
After 30 days of cultivation, drain 10-20% of the water in the pond and replace it with water in the reservoir. It should be noted that the water in the reservoir pond must stay for at least 4-5 days before it can be used to supplement the water in the shrimp pond.
Use 6 paddle wheel aerators to maintain the ideal dissolved oxygen. In the first 60 days, only 4 aerators operated alternately for 24 hours. Install another aerator in each tilapia pen to increase the circulation of water and plankton in and out of the pen.
Harvest and Post-harvest Handling
When the weight of shrimp is at least 30 grams, it can be harvested. The harvesting method is to drain the water and collect the shrimps with a harvesting net installed at the entrance of the pond. The collected shrimps are placed in water with crushed ice to maintain their quality. The shrimps are then sorted according to their size and placed in boxes with crushed ice, transported to the shrimp processing plant, where they are packaged for export.