I have a 25,500 gallon pool with a Hayward DE 6020 filter. I clean the filter regularly (about once every 3 months, or whenever pressure gets to 25 psi). After a cleaning about 2-3 weeks ago, pressure rose quickly, to about 27 psi within 2 days of cleaning and flow dropped, or at least I assume so because the spa fountain dropped noticeably. I cleaned again and the same thing happened, then again a 3rd and 4th time - all in about 2 weeks. Water is clear and balanced and filter was clean when I pulled it out after backwashing. I hose it down each time and usually use a spray degreaser, but did so only on the first of the cleanings mentioned above.
I took the filter into a local Leslie's store and the service tech said it looked fine. It's 7 years old and he said they normally last 7 - 8 years, but longer if well cared for, which mine has been. He couldn't figure out what the problem, as he couldn't see any tears and suggested a service call. He thought it could be a clog downstream from the filter. I just don't want to end up spending $ on a service call only to have the grids replaced, but don't know if there are other diagnostics I can try on my own.
Question - if there is clog, wouldn't the pressure be high at all times? Once I clean the filter and add DE, it starts out normally - around 18 psi - and rises to above 25 over the course of a couple of days. If the filter grids are bad, are they always visibly worn? I did notice when spraying them off the last time that a small section "puffed out" slightly when hit with water. Sign of a tear?
Any help would be greatly appreciated!
P.S - after the last cleaning, the water seemed slightly cloudy AFTER the cleaning. DE flowing into the pool? Also, I noticed small white "rocks" in the pump filter basket. They are hard, but can be crushed into powder. Is this DE? The DE is so fine, I wouldn't think it would form into small rock-like pieces.