I have a cartridge filter and wanted to understand when I should replace it. There are actually 4 filters, I clean them a couple of times a year and they appear to be in decent shape. I've had the pool for 2 years, so I don't know how old the filters are.
10,000 gallon inground gunite pool
1.5 HP 2-speed Hayward pump
Polaris pressure-side cleaner