Credit: Mohamed El Gazaar (Egypt)
The first photo shows two types of tanks during the construction phase while the second photo shows the concrete base of the fattening circular tanks.
Intermediate tanks: The 150-m3 rectangular tanks are used for the production of Nile tilapia juveniles of an average weight of 50-g which are required for fattening phase. These intermediate tanks are constructed of walls of bricks over a concrete base.
Fattening tanks: these 250-m3 circular tanks are made of bricks for walls which are constructed above 30-cm concrete base. Advanced fingerlings (juveniles) produced in the intermediate tanks are stocked in the fattening tanks and grown for about 4 months till harvesting whereas average harvest weight is about 400 g.
The photos 3 and 4 illustrate alternative construction materials such as replacing the red bricks by limestone bricks in the construction of tank walls. The other photo illustrates the possibility of having concrete walls. Usually, chosen tank construction methods is based on the availability of construction materials and hence the economics of the project.
Cement mixed with water sealants is used to coat the tank and prevent water losses through seepage through tank walls.
Aquaculture in the present project utilizes 20% of the total project area. Hence, 80% of the area is devoted to agricultural crops.