Tilapia are regarded as ‘aquatic chicken’ due to their popularity in the agricultural community. Tilapia farming has increased significantly over the past years to an extent they are now domesticated though the use of tanks. The upside of farming tilapia is that they are generally hardy and can tolerate a wide range of environmental conditions. They are fast-growing, able to survive in poor water conditions, eat a wide range of food types, and breed easily with no need for special hatchery technology. Tilapia farming in tanks has been proven as the most productive system as breeding is controlled and conditions modified to allow maximum productivity. Farmers are advised to equip themselves with essential knowledge and skills needed for successful tilapia farming in tanks so as to reach higher profit margins.
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Environmental Conditions
Tilapia farming in tanks is a good alternative to other systems such as cages and ponds. None the less, it is an expensive venture hence the need for knowledge and skill in all aspects of the farming procedure. It is important for farmers to make sure that the water temperature in the tank is suitable for the fish. The recommended temperature for optimum growth is approximately 27oC to 30oC. Water temperature should not be lower than 22oC as this can be detrimental to the health of fish thus affecting productivity. In fact, temperatures that are lower than 20oC diminish growth. To add on, temperatures below 10oC lead to increased fish mortality. Tilapia begin to lose resistance against diseases at water temperatures of about 12oC hence become subject to infections by fungi, bacteria and parasites. Tilapia generally thrive in warmer environments; as such, water has to be heated when tilapia farming in tanks is practised in low temperature regions. In warm climates, tilapia farming in tanks can be practised for up to 12 months.
Housing and Equipment
Tilapia fish farming in tanks is often practised in areas with limited space for ponds or where soils are too sandy for pond construction. Tilapia fish tend to grow well at high densities in the confinement of tanks where good water quality is maintained. This is achieved by aeration and frequent water exchange to renew dissolved oxygen supplies and remove wastes. The trick to efficient, successful and profitable tilapia farming in tanks is to stock with large batches of fingerlings of similar size and age. Tilapia tanks come in a variety of shapes and sizes. Farmers are advised to use tanks made of concrete or glass as they as they are considered the most durable. Other suitable but less durable materials include wood coated with fiberglass or epoxy paint, and polyethylene, vinyl or neoprene rubber liners inside a support structure such as coated steel, aluminium or wood. Take care that the tank is smooth on the inside to avoid fish damage due to abrasion. Some housing facilities for tilapia farming in tanks operate as recirculating systems. They recycle 90% to 99% of the water every day. As such, for tilapia farming in tanks to be a success, farmers should provide fish with appropriate housing systems.
Breeding
Tilapia fish farming in tanks centres on breeding as it determines the choice of farming procedure as well as productivity. Farmers should therefore select fish that is suitable for the available resources as well as prevalent weather patterns. Within 10 to 20 days after stocking brood fish, newly-hatched fry appear in schools that can be captured with a dip net and transferred to a nursery unit. Fish that avoid capture are then removed and the tank drained for the next spawning cycle. Some farmers practise controlled breeding which makes use of net enclosures to capture fish. These ensure that all fry is removed at regular intervals thereby achieving uniformity in size and reducing predation. Male and female tilapia which were previously kept apart are stocked into the net enclosure to begin breeding. A sex ratio of 2 females to 1 male is used to produce large quantities of fry. Some farmers prefer to practise crossing breeding so as to produce an improved breed. There is also a combination of genetic manipulation and hormone treatment to produce improved male species. Tilapia breeders reproduce within 10 weeks to provide fingerlings.
Feed and Nutrition
The diet of tilapia fish is determined by their level of maturity. Their diet should however be highly nutritious in all stages of growth. Farmers favour commercially produced fish food which can be in form of pellets, crumbles and cichlid sticks. Tilapia thrives on a pellet diet. The recommended pellets are those that contain spirulina powder and other greens. They can also be provided with vegetables such as lettuce and peas. In addition, tilapia can also be fed sea food like shrimps. Generally most kinds of foods are suitable for tilapia, provided it is nutritious. Tilapia in tanks can eat wheat, corn, paddy cakes and so on. Although tilapia fish eat a wide range of material, they should not be given fatty foods like pork as it is harmful to fish. In fact, it has been proven to result in sterility and increased mortality. Tilapia fry should be given a complete diet of powdered feed continuously throughout the day. The feed should have a protein value of about 40%. The feeding rate should be approximately 20% of body weight per day and lowered to 30% by the 30th day. When proper nutrition is provided, fish can gain up to 50% in body weight within a few days. For this reason, rations have to be adjusted frequently and accordingly. Feed size should be increased to various grades of crumbles and pellets as the fish grow. Recommended protein levels are 32 to 36% in fingerling feed and 28 to 32% for larger fish. Note that continuous feeding of adult fish leads to aggressive behaviour as they guard the feeding area thus becoming less uniform in size.
Harvesting
Tilapia fish in tanks can be harvested quite easily compared to those from other sources. Harvesting tilapia fish involves selecting mature fish and moving them to a different environment where they are to be killed. Farmers can choose to sell them soon live fish soon after harvest. Tilapia fish must be moved to a separate tank once they reach 180 to 280g where they can get more space to move. The same process can be repeated when they reach 300g. This is mainly done to increase productivity. Tilapia fish are ready for harvesting at 6 to 7 months of age. They can be sold at 400g, however most consumers prefer larger fish of about 500g in weight. Note that the overall yield depends on stocking which is influenced by the size of the tank. However, tilapia farming in tanks generally produces higher yields.
