I have a 13,500 gallon IG pool with SWCG and Lowzone. I have a 420 sq ft Pentair cartridge filter. I clean the cartridges once a year even though I never see more than a few psi pressure increase. When I clean them, there is some dirt and this year, some blue scales from my old solar cover. There's a little staining on the cartridges, but no scale and they clean up nice. I haven't had to soak them yet in anything, just hose them down. I figure this may be the one benefit I get from the Lowzone. I think it burns up a lot of the junk that would build up in the filter if I didn't have the lowzone.