Cartridge filter vs sand filter: Cartridge wins for most residential pools

Cartridge filters catch particles down to 10–15 microns, keeping water clearer than sand filters (20–40 microns). Sand filters require backwashing that wastes hundreds of gallons of water and need sand replacement every 5–7 years. Cartridge filters just need a 20-minute hose-off every few weeks and replacement every 1–3 years, costing about the same over time. Unless your pool gets heavy debris, cartridge is the better investment.