I have a sand filter which is appr. 8yrs old. No problems up to this year. When I vacuum a small amount of dirt the pressure goes up to the point that I have to backwash to get the pressure back up. I put a new pressure guage. Same problem. I removed the sand, cleaned and inspected the laterals and put new sand. Same issue. Once I backwash and run the filter the pressure is stable until I vacuum again. Before this year I have gone weeks without backwashing after vacuuming…
Please help me in this matter.
Thank you,
ShawnK