Your filter is the kidney of the pool — it pulls the fine particles out of the water your pump circulates. Pick the right one and the water stays crystal clear with minimal effort. The three common types are sand, cartridge, and D.E. (diatomaceous earth), and the best choice depends on your priorities: cost, water clarity, and how much maintenance you want.
The old workhorse. Water passes through a bed of filter sand that traps debris down to roughly 20–40 microns. Sand filters are the least expensive up front, simple to run, and you clean them by backwashing (reversing flow to flush the bed to waste). Downsides: they filter the least finely of the three, and backwashing uses a fair amount of water. The media itself lasts about 5–7 years.
Increasingly the default for new builds. Water flows through a pleated cartridge that catches particles down to about 10–20 microns — noticeably clearer water than sand. There’s no backwashing, so they save water (a real plus during Georgia summer watering restrictions); you simply remove and hose off the cartridge a few times a season and replace it every few years. They cost a little more than sand but are easy to live with.
Diatomaceous-earth filters coat a grid with a fine powder and filter down to roughly 2–5 microns — the clearest water you can get. The trade-off is maintenance: you backwash and then “recharge” the filter with fresh D.E. powder, and the grids need periodic cleaning. Great for owners who want showroom-clear water and don’t mind a bit more upkeep.
Sizing matters more than type. An oversized filter runs cleaner and longer between cleanings, and it pairs beautifully with a variable-speed pump for low-cost, quiet circulation. When we design a pool, we size the filter and pump to the specific pool — not a one-size box.
Whatever the type, watch the pressure gauge: when it climbs 8–10 PSI above the clean baseline, it’s time to clean or backwash. Don’t over-clean a cartridge — a slightly dirty cartridge actually filters better than a brand-new one. Read this alongside our complete maintenance guide.
Sand: set the valve to "Backwash," run until the sight glass is clear (about 2 minutes), then "Rinse" for 20 seconds and return to "Filter." Cartridge: turn off the pump, remove the cartridge, and hose it top to bottom between the pleats; soak it overnight in filter cleaner a couple times a year. D.E.: backwash, then add fresh D.E. powder through the skimmer to recharge the grids; deep-clean the grids each season.
An oversized filter runs longer between cleanings, traps finer debris, and lets you run a variable-speed pump slowly and cheaply. Undersize the filter and you'll fight cloudy water no matter how good the chemistry is. When we design a pool, we match the filter and pump to that specific pool's volume and flow — not a one-size box off a shelf.
If clarity is slipping, work down this list: is the pump running enough hours? Is the filter pressure 8–10 PSI above its clean baseline (time to clean)? Is there channeling in old sand, a torn cartridge, or D.E. caked on the grids? And finally — is the chemistry balanced? A filter can only do its job when circulation and chemistry are doing theirs.
For most homeowners, a properly sized cartridge filter is the sweet spot — clear water, no backwashing, and it saves water during summer restrictions. Sand is cheapest; D.E. filters the finest.
When the pressure gauge reads 8–10 PSI above its clean baseline. That's usually every few weeks to a couple of months depending on use and filter type.
Yes — an oversized filter traps finer debris, runs longer between cleanings, and pairs perfectly with a variable-speed pump.
CraftYourPool designs and builds custom in-ground pools across Northeast Georgia from our home base in Braselton — factory-direct pricing, a full 3D design of your actual backyard before you commit, and pool-ready in 6–8 weeks. We’re a licensed Georgia residential contractor and certified Pentair installer. See financing options or get a free consultation — call (762) 425-9249.
