I purchased a "Poolskim" secondary skimmer. When I opened it I learned it needs to attach to a threaded return line. My returns are 1.5" smooth pvc and use a slip style eyeball to direct the water. Is there a way to convert a smooth pipe to a threaded one? It seems there should be a coupler of some kind that can glue into the smooth return line and have a threaded part to screw the poolskim onto. I just cant seem to find one. If anyone can point me in the right direction it would be appreciated. Thanks