We've got a Jacuzzi Sherlock 160 cartridge filter. Filter body manufacture date is 2005, and it's got an aftermarket cartridge in it now, so it's maybe around 4 years old at a best guess. Cleaned cartridge when closing; it runs about 20PSI with filter gauge about 5' below pool water line. Previous owner said that's about what it usually runs, he cleaned when it got up to around 25PSI. Ran whole last summer and it didn't get up to 25PSI. Pool water is not particularly clear, always looked a tiny bit cloudy.
I kinda get that cartridges need replacement when they get so gunked up that cleaning them doesn't reduce filter pressure adequately, but do they also eventually fail by letting too many tiny particles thru? I've inspected for tears or holes, and gaskets still seem reasonably good.
Thanks as always for any advice!