I have a 10K fiberglass pool with Hayward equipment, SuperPump w/A.O. Smith 1 HP 2 speed motor, S244T sand filter. I have sand from the filter coming into the pool. I've taken the filter apart, checked the laterals, no breakage; opened the VariFlo valve, found some sand, cleaned it out, greased with silicon, reassembled and still getting sand coming into the pool. My pool store says that the VariFlo spider gasket (I took it to them) can't be replaced. IS this really the case? THe gasket is white and kind of chewed up. IS there any way to replace the gasket? Is there something I haven't checked that could be the cause of the sand in the pool?