About a week ago I noticed the water level dropping on my pool. Wasn't able to troubleshoot until this weekend due to work and constant rain. I'm seeing bubbles in both return lines. I checked with both skimmer and main drain, skimmer only and main drain only. Yesterday I backwashed and set my valve to skimmer only. When I started the pump I wash having trouble getting prime. I then set valve to skimmer and main drain and pump primed and seemed to be running fine. I woke up this morning and pool had leaked to below the skimmer. I checked the backwash line and water was leaking out of it. I changed the valve to main drain only and the leak slowed but was still leaking. I am thinking this is something with the multiport valve on the filter (Hayward Model S244T sand filter). Does anyone have any suggestions on this?