In the past years my filter pressure was normally around 20 PSI. This year i have been running around 26-27 psi which usually means its time to backwash at this pressure. My issue is the filter doesnt need back washed, i tried that and the pressure wont go down. I actually backwash about 10,000 gallons thru it when i opened the pool this was a partial drain and fill to bring mu CYA down ... My initial thought was maybe last year the pool company i had close the pool didn't do a good job cleaning the filter. So yesterday a took it all apart and thoroughly cleaned all the fins.... put it all back together and still 26 psi before adding any DE. It appears as if the flow and pressure on the return is the same it always was in past years.
Any ideas from the experts