For years I used sand filters and never had a problem with them. With the new pool (5 years ago) the filter included was a cartridge filter. After 5 years with the cartridge I have been dying to go back to a sand filter. After reading about saltwater chlorinators, I ordered the Intex SWCG and a 3000 gph sand filter system. I'm still waiting for delivery of the SWCG but I received and set up the filter. It started cleaning like gangbusters! I was thrilled. After running for several hours the pressure was up and I wanted to backwash the filter. I shut the pump off, and moved the 6 way valve to the backwash. When I turned the pump on it started backwashing... for about 5 seconds. Then nothing. If I put it into rinse I get full flow out of the backwash line. But when I put it in backwash, it flushes for about 5 seconds and stops again. After doing this several times, it backwashes at almost no pressure. Any suggestions would be appreciated.