Please explain this plumbing to me.
The left valve controls suction. The more left the valve, the more the skimmer works.
The right valve controls return. Turned left the whips operate, turned right the wall returns operate.
When the left valve is turned right and the right valve is turned left, nothing works and the psi drops from 20 to 12.
I checked to make sure the valve handles were properly attached, pointing in the right direction, they are.