Tilapia Powered Aquaponics to Optimize Land and Water Use for Safe Food Production from the Rooftop

Abstract—Tilapia powered vertical aquaponics system (TPVAS) is an effective way to increase crop production in a food desert city per unit rooftop area by extending crop cultivation into the vertical dimension to feed the ever-increasing population of the world and keep the city-pollution free and cooler. Experiments conducted over the years to assess the viability of tilapia powered lettuce, strawberry, water spinach and mint production in the media-based vertical aquaponics system at the rooftop and lab of Bangladesh Agricultural University, Mymensingh, Bangladesh. The wastewater of the tilapia tank irrigated to the 4 feet height and 3-4-inch diameter vertical plastic pipes holding 15 to 18 saplings in each pipe which passing through the coco dust, coco coir, water hyacinth root, and brick chips media then return into the fish tank again. Fish growth performances, nutrients availability, and their use assessed. The mean length and weight gain of tilapia were 2.95 (±0.83) to 11.77 (±2.49) cm and 32.71 (± 9.43) to 170.38 (±78.7) g. The feed conversion ratio (FCR) were 2.5, 2.35, 2.33 and 1.5 and survival rates were 96, 78, 85 and 98.33% for lettuce, strawberry, water spinach and mint based tilapia aquaponics systems. The fish and vegetable production was 30.64 to 135.20 and 12.47 to 123.25 MT/ha/90 to 120 days respectively. Among the four media, coco coir produced the highest crop than the others.Therefore, it is concluded that the TPVAS is suitable and capable of producing fish and vegetables at the rooftop keeping the rooftop cooler and greener than nearby traditional roof gardening buildings.