Well, I went ahead and spent $100 for new resin. Relatively simple to do. Old stuff was opaque white with black bits (charcoal). New stuff shiny, golden and transparent. Cleaned the valve too. About two weeks with new resin, but doesn't seem to be 100 percent. Definitely better, but water doesn't have the expected "slimy" feel. Test strip indicated 3 grains of hardness. Seems to cycle OK; backwash, brine, etc., but just can't be sure it's working right. Any thoughts?