I just wanted to share my experience with my cartridge filter. I has one of those intex saltwater cartridge filter pump units that uses the size B filters. At the beginning of last year I bought 4 of them seeing people on this forum had to change them often. I know the size of my pool is not that big but it seems unreal that I only used one filter ALL of last season and for 2 weeks this season and rinsing of the filter last night I realized that it is still as white as the new ones. The only thing I did different than normal is I rapped the filter with a piece of screen from an old screen door. Flow is still perfect through the filter as since it is a combo unit it would shut off and say low flow, also water is crystal clear and rinsing the filter is a breaze. Take off the screen easy to hose as it is only large bugs, hair, etc. And the filter is only small particals that are easy to rinse. Just thought I'd share since I have learnt alot from others on this forum!!!