We've been having a lot of bubbles coming out of the pop ups and returns when the pool turns on. There was a leak on the DE filter and we got a new O ring. Where else do we check? How do we know for sure which O-Ring needs replacing or is it time to replace most ORings or all until we figure out which is the culprit or could something else be letting in air or causing this problem? I wondered if there could be something stuck in a pipe or something as this problem started months ago when we were overdue for a backwash/breakdown of the DE filter. We have the pool company coming out Wed due to salt cell/panel not working but we're already going to resolder K-1 on motherboard if it needs resoldering or get a new SWG system as pb would charge quite a lot. I'm wondering if I should cancel appt for Wed or will they be able to help us identify where the bubbles r coming from, at least. For a $150 trip fee I can live with bubbles although if it can damage something later I want to get this taken care of. I'd feel better if pool ran without bubbles like it used to. thx!