First time closing myself. I am reading about expansion plugs, however, we seem to have threaded pvc(or hard rubber) plugs with a rubber O-Ring gasket. I wasn't around for when the pc closed and opened, but I am assuming I can just wrap a little teflon tape on the threads and use these plugs for the returns...correct? We have Gizmos for the skimmers. Does the Gizmo negate the need to put anything else in the skimmer to prevent ice damage?