Just one foggy thought left for me. When my sand filter pressure goes up, needs a backwash, the panels do not stay full with water. You start to see bubbles in the returns and can hear the vacuum break opening/closing. This is my audiable alarm to backwash!

Is this an indication how a low speed pump would work on my pool? With a low speed at 1/2 gpm, is there enough flow to keep the vacuum break closed, with a clean filter? Right now I have a 1hp pump and the panels' highest point is 20'.

Joe