I got a message from CAD that by removing the red gasket, it seals better and gets smoother turns. I tried it on mine last week and its so much looser and the bottom 2 plates stay put. no micro-bubble leakage and I can turn with just 2 fingers now.
they say by removing the red gasket, its very much like the way the larger PLS skimmers are. those don't use the red o-ring.