The wall return filter in my Polaris 360 is clogging with blackish granular debris. This happens over 4-5 hours. I replaced any leaking "fins" in the DE filter last winter as this clogging was happening last summer. Figured debris was getting through the DE filter into the Polaris return. I have backwashed the initial post-opening DE.
I am at a loss to determine the source of the debris. Pump impellers? The big "clock" valve? holes in the DE filter still?
Chlorinator goes through a separate line.