Cartridge filters are better for small pools.

Cartridge filters. For a small pool — say, under 15,000 gallons — cartridge is the smarter choice.

Sand filters require backwashing, which dumps a ton of water down the drain every time you clean them. For a small pool, that’s a waste. Cartridges just need a quick rinse with a hose every few weeks and a replacement once a season or two. No water loss, no backwash valve mess, no giant tank taking up space.

Sand filters are tanks. They last forever when maintained, but they’re overkill for a small setup. You’ll spend more on water and complexity than you save on initial price. Cartridge filters are simpler, quieter, and filter finer particles (down to 10–15 microns vs. sand’s 20–40). That matters when your pool is small and you want crystal clear water without a lot of fuss.

One trade-off: cartridges cost money to replace. But for a small pool, you’re talking maybe $30–60 once a year. A sand filter’s backwash valve will fail eventually, and replacing sand every few years is a pain.

Your small pool doesn’t need brute force — it needs simplicity.