Air in sand filter

[Dr. Kwak]

Thanks, I appreciate the responses. I only see the occasional grain sized bubble swirling around in the pump basket. One thing I did find
over the weekend is it only happens when I have the main drain line open and the skimmer line closed. When I open both lines the filter
stays completely filled with water. Perhaps the is a leak in my main drain line then? The water level is fine, no air sucked into the skimmers,
and the weirs are flapping like they should. I did order a new gasket for the pump lid, the current one is a a few years old and was rarely lubed.

[waste]

Thanks for the feedback!

It sure sounds like a 'pin hole' leak in the MD line. I'd say it's something to keep an eye on, but not loose sleep over