AQUAPONIC PRODUCTION SYSTEM OF LETTUCE Lactuca Sativa AND NILE TILAPIA Oreochrmis niloticus ARID LAND AREA AT A COMMERCIAL LEVEL
Arid Zones such as United Arab Emirates strategic suffers of inability to securing high quality food products and conservation of scarce freshwater that can be used to fulfill other strategic goals. Aquaponic is the most efficient food production system that uses less that 90 percent of water used in convention crop production. The advantages of aquaponics includes crops grow faster than conventional method, no pesticide, herbicide nor fertilizer are used. Three aquaponic units each contain a 400 m2 greenhouse with plantation area 120 m2 in four turfs (each .2*24* .4 m3 covered with perforated Styrofoam sheet) , two circular fish tanks with 7.7m2 fish tanks connected to water treatment units include swirl separator for mechanical filtration followed by two biological filter tanks with plastic media then a CO2 stripping unit. Water moves from fish tanks to the water treatment system and plantation raceways by gravity and return to fish tanks using a 3Hp water tanks. The system was aerated by 5Hp air blower. Fish Oreochromis niloticus tanks were stocked with 100 fish m3 with an average weight of 48.3g. Nile tilapia were fed to satiation three times a day a floating commercial tilapia diet. Raceways were planted at a rate of 24 lettuce Lactuca Sativa seeds per square meter. Water consumption from evaporation and evapotranspiration and cooling system were measured as well as electricity consumption using meters. Lettuce production was 8,424 heads of lettuce weighing 2.182 tons in 30 days from seeds. Fish weight reached an average of 62.1g fish in during the same duration. Light intensity average was 350.2 Lux, water used to recover evaporation and evapotranspiration was 32.85 m3, water consumption for cooling system was 6.67 m3 and electrical consumption was 7181.1 Kw during the same duration. Water temperature ranged from 23 to 25ċ. Water quality were monitored as followed; DO 7.3 to 8.6, pH 6.9 to 8.3, NH3 0.07 to 0.38 mg per liter, NO3 4.1 to 7.6 mg per liter. Trace elements changes in water samples for Al, Bi, Co, Cr, Ga, Li, Mn, Mo, Ni, P, Pb, Rb, Sb, Sc, Se, Sn, Ti, U, V, W, Zn, Zr, Ba, K, Mg in water was measured using ICP-MS.