Sand filters are fine for most pools.

For most backyard pools, a sand filter is the simpler, cheaper, and more durable choice. Cartridge filters catch finer debris, but they cost more and need regular manual cleaning. Unless you have a very specific need (like a pool surrounded by trees that drop tiny leaves), sand is the way to go.

The main difference is how they trap dirt. Sand filters use graded sand to catch particles down to about 20-40 microns. You backwash them (reverse the flow) to flush out the junk, which uses some water but takes two minutes. Cartridge filters use a pleated fabric that catches particles down to 10-15 microns — cleaner water, but you have to take the cartridge out and spray it down with a hose every few weeks. That gets old fast.

Sand filters last forever (replace the sand every 5-7 years for like fifty bucks). Cartridge filters need new cartridges every 1-2 years, and those are not cheap. Sand also tolerates algae blooms and heavy use better without clogging instantly.

Yes, sand filters don’t polish the water as well. But the human eye can’t tell the difference between 20 micron and 10 micron clarity. And if you run your pump long enough and keep chemicals balanced, a sand filter will keep your pool crystal clear.

Unless you’re a pool perfectionist with a fussy above-ground setup, save the money and get a sand filter.