The filter and pump is higher up than the pool. I also have a spa connected to the system. DE starts to enter thru the skimmer and drain when the pump shuts off. There are no signs of water leaks from the pump and the filter. Last week I did a pressure check on all the pipes when the pool was empty. This is my first time starting the pool's equipment since I just moved in 2 weeks ago. The pump is a brand new variable speed pentair. There used to be a check valve which i took out in the suction line just before the pump. In lieu of the check valve, I raised/extended the 3 way valve (skimmer/drain) for the suction higher up than the pump basket in hopes that I can eliminate the need for a check valve. Could it be possible that I have an air leak from the filter but no signs of water leak? Should I just install a new check valve and call it a day?