I have a 33ft round pool w/ sand filter. Ran last year for first year(prior owner ran for 6 yrs) with no issues. Pump/filter runs fine at 17 psi steady state. When I put the vacuum skimmer plate on to start vacuuming, I lose pump prime every time. I force water into the skimmer plate to get the air out of the hose. I'm able to keep the plate under water while placing into the skimmer. Last year, I would usually lose prime once, but by the second time it would normally work. I tried last night about 20 times before I gave up.

The water does not totally recede in the pump skimmer(Goes down about half way). The suction line continues to flow into the pump, just not fast enough to build pressure and function the vacuum. Any suggestions?