The best pond system for growing catfish is earthen ponds; They are less expensive to build, offer a natural environment for the fish to thrive in, and are simpler to manage.
In order to construct a successful earthen pond, it is crucial to test the soil for clay content, take the amount of land available and the needs of the farmer into consideration when choosing the size and shape of the pond, and make sure the pond has a slope of 45 degrees for easy access and maintenance.
Aerators may be required if the pond is deeper than 5 feet to prevent asphyxia (a condition that rises when the body is deprived of oxygen) which can lead to severe mortality among your stock.
Earthen ponds can be constructed manually or with earth moving machines like excavators. Here are a few steps to follow. (Kindly note that these steps are optimized for cost reduction)
Mark out the area for construction of the pond, using lines. Understand that the bottom of the pond should be narrower than the top of the pond, in order to get the desired gradient.
Thus a 30ft by 60ft pond should start with roughly a space of 40ft by 70ft.
The pond walls should be slanted by at least 45%
The bottom of the pond itself must be slanted towards the general slope of the land. If the land is slanted south, slant your pond south etc.
Thus ensure to instruct your excavator operator to do same. i.e start from 70 ft x 40 ft at the top but end with 60ft x 30 at the bottom (this is an example used to illustrate the pond, it doesn’t mean all pond sizes should be this).
Space between ponds should be at least 20ft apart. This is to give room for future pond maintenance, if the space between is less than 20ft, an excavator may struggle to reach it in the future.
We recommend a depth of 7ft for African catfish production, 5 ft of which would be the level at which you fill your water, giving 2 ft above.
Install an inflow and outflow system. Inflow is the point where the water comes into the pond, we do not recommend allowing running water to come into the pond. If a river is your source of water, we recommend a flow through system, where the water comes through your inlet and flows back through the outflow, consistently providing your catfish with fresh water.
If your source of water is a borehole, an outflow is still recommended. Most earthen ponds are open pond systems, rains can increase the volume of water, and running water can break the barriers of your pond, having an outflow in place, ensures that your pond is secured in the event of excess water flowing to it.
Get yourself a 3 inch pipe. mark the estimated water level (e.g. 5ft), insert your PVC at that point, at the lower end of your pond, such that water can easily flow out the pond.