I have a question concerning depth and vortexing in a water basin. My company and I are designing a system comprised of a large U-shaped basin of water (1000000L). At the end of the basin I wish to remove the water to be filtered then returned to the beginning of the tank. The dimensions of the end of the basin are 10m widex0.3m deep with the entire tank being 30cm deep. We were planning on removing water at a rate of 5.3m3/hr (~1.5L/s) but are unsure as to whether this rate will cause a vortex of air to be drawn into the pump since the water is so shallow. We have been searching for some time now and cannot find any way to confirm whether this will occur or not. If possible could you please indicate to us whether this vortexing would occur or not and/or if possible what suction velocity into the pipe would cause it to occur. We are still in the early stages and have not yet selected a pump or pipe size. Thank for your help and any input would be greatly appreciated.