Have a stand pipe that i cant get quiet. I have a 1/4" aprox. hole in the cap and still seems to be sucking air. I have drilled more holes in other test caps with little improvement. If i cover a little bit of the 1/4 " hole it sucks the water down below the tee and looses prime then surges. I have changed the drain line to flex pipe and it hase smoothed the flow out a lot. I just cant get a grip on the stand pipe "tuneing". I am including a pic of the stand pipe and sump. Please help!