I posted an earlier question about DE returning to my pool. Got no response so maybe I can get feedback on this. On a Pentair DE filter lower housing is the intake (bottom fitting) and the return (top fitting). The return has the 2" PVC pipe which goes up the side to the manifold. When I fill that tube up with water I can see it streaming back into the tank. Is there a oring that needs to be replaced and if so how do I get that bulkhead off the tank? Please help.