 As the water rotates, it also disturbs organic waste at lower water layers, forcing it to the top.Rotational force the pool return jets create is the most important part of cleaning the pool water and pushing organic waste across the mouth of the skimmer.With a correctly designed and operated swimming pool, this circulation is visible and after a period of time, reaches even the deep end, inducing a low-velocity vortex above the main drain due to suction.