When you live outside the tropics, you can grow tilapia in a backyard pond where they can thrive if you keep the water at the needed temperatures. A fish with firm, white flesh, tilapia survive in poorer water conditions and lower oxygen levels than many other types of pond-raised fish. But they prefer a water temperature of 82 to 86 degrees Fahrenheit, as they grow slowly in 68 degree F water and may die when the water temperature drops to 50 degrees F. Many tilapia ponds average one-half acre or larger in size, but are only 3 to 6 feet deep, so a large backyard or acreage is a necessity.
Before constructing a tilapia pond, consult local grading and pond-building construction codes or professionals. To successfully grow tilapia year round, you must live in a year-round warm climate or heat the water when water temperatures drop below livable temperatures for the fish. Conduct a soil test before grading to determine its makeup, as this influences the type of pond and construction methods. For example, clay soils tend to hold water, while sandy soils don't.
A bulldozer or other earth-moving equipment removes the soil to the desired pond depth. Gently slope the sides with a two-to-one slope between the top of the levee, its sides and the bottom of the pond. Build the levee high enough so that its top measures approximately 8 to 12 inches above the water level. Many levees range from 10 to 16 feet wide at the top, allowing for vehicles to drive on them.
Smooth and firm the bottom of the pond. Remove any debris such as tree stumps and rock outcroppings. Rake all organic material, such as leaves and weeds from the bottom of the pond. Test the pH value of the soil at the pond's bottom and sides to ensure it is within the desirable range for tilapia, which requires a neutral to slightly alkaline 7 to 9 pH. A 1 to 2 percent bottom slope allows the ponds to drain successfully.
Install a water inlet pipe approximately eight inches above the desired water level. Construct an outlet pipe so it is possible to completely drain the pond during and after tilapia harvest. Cover the inlet and outlet pipes with screen with small enough holes to prevent fish from getting into the pipes. By adding a harvesting sump to help drain the pond, you can successfully assemble the fish during harvesting. The sump also allows for cleaning of fingerlings and fry from the pond before reuse.
Things to Consider
Plant grass and other suitable vegetation around the pond to reduce soil erosion. Install a cement or plastic liner if the soil texture doesn't allow the pond to sufficiently hold the water. Carefully watch for burrowing animals such as moles, gophers or muskrats that can make holes in the levee. To raise a larger number of tilapia in the pond, add an aeration device to increase the oxygen content of the water.