1. Culturing site
For culturing site there are few aspects that need to be considered which are topography, Weather condition water supply, accessibility, and soil condition. The area selected is usually located near to supply of water with salinity ranging from 10 to 20. The area should also be free of any pollutant with soil pH from 7-8.5. Pond elevation should also be within the reach of ordinary high tides. Easy access to support facilities such as electric power plant would be an advantageous. …show more content…
This is so the dispersal of feed can be distributed evenly throughout the pond. The following are the recommended size for culture pond by different culture method: intensive culture is from 0.5-1.0 ha semi intensive is from 1.0-2.0 ha and extensive at 1 to 10 ha. The height of dikes should be at least 0.6-0.7 above desired water depth and it must not be to steep to avoid erosion. Supply canal can be design according to the size of the ponds, the supply canal are used to convey the water from the reservoir to the ponds by gravity or pumping. Gates for inlet and outlet are required in order to fill and drain the water of the pond, the size of the gate also depends on the size of the pond. The aeration system is required for maintaining dissolved oxygen level within the …show more content…
The soil must sample in order to detect the organic content and pH of the soil.The soil pH was recorded in the pond with the help of cone type pH meter. Then the pond can be cleaned, there are two method in cleaning pond which are dry and wet method. Dry method is used where the pond can be dried completely. After 30 days the waste are taken out of the pond, while wet method is used where the pond cannot be dried completely. Pressure washing is used to remove the waste from the pond. There are two me To avoid topsoil the pond bottom was scrapped 2 to 4 cm by a tractor, the pond bottom was then ploughed horizontally and vertically a depth of 30 cm to remove the obnoxiuous gases, oxygenate the bottom soil, discoloration of the black soil to remove the hydrogen sulphide odour and to increase the fertility ( Shailender.M. et al , 2012). The next step in pond preparation is eradication of predators. There are several method in controlling the unwanted species. One of the method in preventing the entry of unwanted species is by using an appropriate screen during water management which should be installed at the front gate. Another effective way to remove unwanted species is the use of saponin from teaseed cake applied at rate of 10-25 ppm (Cook, 1976). Commercially rotenone powder extracted from derris root are also known to be effective in eradicating unwanted species. If the pH is not at desirable pH liming should be done.