A system for efficiently circulating water in a large volume of rearing space for aquatic organisms, comprising an impervious enclosure for containing the water and aquatic organisms and a pump for pumping water from an intake duct through intake ducting to a flow diverter, which then directs a flow of water radially outward within the enclosure to directly induce a circulation of water within the enclosure. The ‘center drive’ circulation pattern is sufficiently uniform to provide optimum rearing conditions for cultured finfish, while also ensuring that solid wastes are swept toward the central drain, even in a very large tank.
