22K Gallon in-ground
1 HP WhisperFlo
25' 1.5" Hose
I just installed a new 1 HP 2-speed Pentair WhisperFlo with a 31" Hayward sand filter. When drawing from the skimmer basket or the vacuum inlet on the side of the pool (without vacuum hose/plate) everything looks great with about 11 psi on the filter.
I hook up the vacuum plate to the hose and lower it in the deep end slowly and shaking it every couple feet to release air bubbles and as soon as I insert it in the vacuum inlet the pump basket goes down to about 2/3 full and pressure drops to 3 or 4 psi. I am able to vacuum the pool but not enough suction to get my old Hayward PoolVac up the inlcine from the deep end to the shallow end.
I have 1.5" inlets and 1.5" pipe up to the Jandy diverter. Then 2" pipe to the pump and filter and it gets reduced again before the return pipe goes underground.