Abstract: A module type aquaculture tank having a stepwise recirculating aquaculture system according to the present disclosure may include a main fish breeding water tank including first, second, third, and fourth edges and having a square plane, an intermediate fish breeding water tank disposed adjacent to the first edge of the main fish breeding water tank, a plurality of recirculating filtration tanks arranged adjacent to each other along the third edge opposite to the first edge of the main fish breeding water tank, and an air lifting Venturi apparatus including a plurality of Venturi pipes arranged along the edges of an inside of the main fish breeding water tank and an air guide obliquely extending from an upper end of each of the plurality of Venturi pipes upward in an air spray direction.

Abstract: The present disclosure relates to an air lifting Venturi apparatus including a first inflow pipe extending in the form of a tube to guide inflow of water; a second inflow pipe extending in the form of a tube to guide inflow of air or oxygen; a Venturi pipe including a through passage having a neck portion having a diameter smaller than a diameter of an inflow port between the inflow port and an outflow port, wherein the first inflow pipe is connected to the inflow port and the second inflow pipe is connected to the neck portion; a spray nozzle connected to the outflow port of the Venturi pipe; and an air guide extending obliquely from an upper end of the Venturi pipe toward an upper portion of the spray nozzle in a spray direction.

Abstract: A module type aquaculture tank having a stepwise recirculating aquaculture system according to the present disclosure may include a main fish breeding water tank including first, second, third, and fourth edges and having a square plane, an intermediate fish breeding water tank disposed adjacent to the first edge of the main fish breeding water tank, a plurality of recirculating filtration tanks arranged adjacent to each other along the third edge opposite to the first edge of the main fish breeding water tank, and an air lifting Venturi apparatus including a plurality of Venturi pipes arranged along the edges of an inside of the main fish breeding water tank and an air guide obliquely extending from an upper end of each of the plurality of Venturi pipes upward in an air spray direction.