The aquaponic unit operated continuously with aknowndensity of fish biomass to maintain stable bacterial populations. Common carp (Cyprinus carpio), grass carp (Ctenopharyngodon idella) and silver carp (Hypophthalmichthys molitrix) were stocked in the rearing tanks (diameter 1.2 m, water depth 0.75 m, and water volume 848 L) at 15, 20 and 15 fishm−3, respectively and cultured for 6 months. The mean mass of fishes stocked ranged from 160 to 180 g.The fish were always fed three times daily with a pellet diet containing46% protein at amean rate of3%of body weight per day (Table 1). The fish were fed and defecated entirely within the fish tank. Water from the fish tank was continuously (24 h day−1) pumped to the system via the water pump, thus biological filtration of the culture water was constant. Tanks were harvested after 6 months. The fishes were weighed and counted.