I am trying to figure out if I have everything correct with my pump and filter.
I have a sand filter. 300 lbs of sand. Flow rate is 60gpm.
To my best estimate, I have about 20,000 gallons of water in my inground vinyl lined pool. I have two intakes (skimmer and then another intake on the side of the pool about 12-24 inched below the surface) and one input.
My pump is a 3/4 HP Hayward Superpump that states it is .75kw. As far as I know, it is only one speed.
My question is:
Is my filter and pump sized correctly? It seems that at times it sucks so hard that air gets pulled in the pump. I have checked for leaks over the summer season. I have found some and fixed them. When both intakes are open and the pressure on the filter is low after backwashing, I am fine. If I move to one intake or if pressure has gone up from a dirty filter, I see air being sucked in.
Do I need a smaller filter?
Do I need a less powerful superpump?
I have heard about these variable speed pumps or two speed pumps. Will this help? I don't know anything about these pumps at all.
Thanks for your help in advance.