Longitudinal flow installation (1) for farming of aquatic organisms, wherein the longi- tudinal flow installation (1) comprises a raceway (2); wherein the raceway (2) is struc- tured to be filled with water for allowing aquatic organisms to be accommodated; wherein the raceway (2) comprises an inlet portion (21) for water and an outlet por- tion (23) for water, and the outlet portion (23) is provided with a first drain (7) for the water; wherein the longitudinal flow installation (1) is provided with a fluid supply (41, 45) for allowing oxygen to be supplied to the water, and wherein the longitudinal flow installation (1) is further provided with at least one return conduit (3) for circulation of the water in the raceway (2), wherein the return conduit (3), in an inlet portion (31) and an outlet portion (33) thereof, is provided with a submerged, water flow-through and organism-excluding element (35, 39).