Intex 2650 sand filter,back washed for first initial setup for the year. Rinse the back onto filter and noticed the water level in the sight glass or sediment window lowered to about half. Checked the intake valve and all good, doesn't seem to be air trapped in system. Could the sand filter be restricting the flow? I have great pressure coming out of exhaust in the pool. Actually can shoot halfway across my 18' if I angle the eyeball. Any ideas?