I have a brand new Waterway Carefree sand filter (well, not brand new, but never been used). I just got it set up and filled the pool to the skimer to test it out. When I set the valve to Filter, I get a fair amount of water going to Waste as well as to the pool. Guy at the pool store said it needed a new divertor gasket, could that be right? This filter has never been used and looks brand new, why would the gasket be bad. He also said they recommend buying the divertor as well because it comes from the factory with the gasket glued on. Any thoughts?