Hello- See if I can explain this properly- Underground pool.
We added a new pump this season to replace an old one, had the pool store do it , I bought the pump myself, direct replacement. Also new Jandy valve
Seem to be getting a lot of bubbles in the filter basket, but just on top ( swirling) New connections from return to the filter itself. I checked the connection at the Jandy Valve, out of pump, multi port and in/out on the Sta-Rite sand filter.
All O rings seem fine, triple checked BUT am getting air in the sandfilter. After about 2 hours running, no pressure building, but I can release a LOT of air from the top valve on the filter, as if 1/2 the filter is full of air.
We see no air coming from the return into the pool.
I've been correcting this problem now by leaving the air valve on top of the filter open slightly to release the extra air.
Again, no pressure building up on the gauge but a lot of air.
Have not opened or checked the filter, it's the older two piece filter with the knobs around the middle type thing. Filter seems to work, shows about 19 pounds. Probably open it up next season, hasn't been opened in a year, last check sand was OK. More concerned about the air.
We do shut the pool down every night and the level in the filter basket stays full, showing that we aren't leaking at night and retains some internal pressure-
SO... thought on the air problem, or is there one. Pool guy said it's OK as long as you don't get the water level to low in the filter basket. BUT why the air ?