Recently, I've noticed that I'm starting to get bubbles in my closest return line from my pump (maybe 10 ft from pump), but not in my other two returns (very rarely in one about 17-18 ft away, none in furthest return).
I noticed the bubbles, about 1/4 inch in size or smaller started after my SWG began working. They are not the champagne size that some suggest could come from the chlorination process.
I have also noticed that I am getting some air in the strainer basket (starts at about a quarter size, then gets to the size of a small child's basketball [diameter] but grows no larger), and that I get air in the top of my filter, even after bleeding it. In fact my filter won't fill completely with water unless I bring my pump up to 1250 rpm.
I am currently running my pump at around 800-1000 rpm, achieving good flow on my SWG.
I have attempted:
Reseating and lubing the O ring on the strainer basket lid.
Reseating and resealing the drain plugs on the pump.
Reseating and lubing the O ring on the check valve.
Smearing silicone lube over the joints leading up from the ground to my suction side.
I'm not really sure where to go from here. There are no obvious leaks or areas where air is being sucked in.
The pipes below ground have been pressure tested prior to install, 3 months ago.
Basically, are the bubbles really harmful, i.e. do they really impact my suction? Would they impact my ability to use solar water heating?