There is money in fish farming if farmers adhere to good practices.
Godfrey Kityo from the National Fisheries Research Institute in Kajjansi, Wakiso district, says for any system that a farmer chooses, he or she should seek help from experts.
Kityo says pond sizes differ, but what should not change are the factors of location and depth.
“Many farmers think that every site with water, is suitable for pond construction, however, the water should be enough and able to flow by gravity. But some farmers construct a pond without inlets and outlets, which is wrong,” he says.
Kityo adds that a pond should not be constructed in an area that floods whenever it rains. “If you do so, your fish will be swept away by floods,” he says.
Kityo says: “Some have wrong depth measurements. Some have no proper water outlets and inlets and lack the recommended gradients.”
It should have conditions, such as a permanent source of water, the soils should have some clay because it holds water better than other types.
He says the topography should offer the gravitation flow of water into and outside the pond because fish uses a lot of water and if the water is stagnant, the fish yields will be affected.
The pond should have a depth of 1 metre towards the inlet and 1.2 metres at the deeper end.
There are two ways of digging a pond. Experts say farmers with the means can hire tractors to excavate the ponds, while others can use manual labour.
The average cost of using a tractor to construct a 20×40 metre pond is sh10m. A tractor takes a shorter time, compared to manual labour, although manual labour is cheaper.
The pond must be rectangular, because this makes it easy to maintain, especially when guarding it against silting.
What to know about stocking
Stocking is important for fish farmers because many of them do not know the right density or amount of fish to be stocked in a pond.
“Many think that they can get a lot of fish by stocking heavily, not knowing that each pond has a maximum capacity and once it is overstocked, the fish will not die, but it will not grow well. They will experience stunted growth, which will automatically kill the market,” Kityo says.
Stocking depends on the amount of water in the pond and not on the size of the pond.
“Get an expert to help you determine the cubic metres of water in the pond before you decide how many fish to put in,” he says.
If well fed, fish should be weighing at least a kilogram by the eighth or ninth month.