Quote Originally Posted by PoolDoc View Post
...ANY cartridge or filter media is a potential reservoir of accumulated oxidizable 'goo'. 2. For the same reason, clean the filter cartridges. Be sure to do it correctly. Spraying them off (with the hose; NOT with a pressure washer!!) is a good intermediate cleaning, but a full cleaning, which should remove any oxidizable 'goo' that could create chlorine demand takes more. See http://pool9.net/cart-clean/
Still want you to do this..... Can't hurt and can only help.