Equipment Guide
Pool Filter Types: Sand vs Cartridge vs DE
Your filter is half of what keeps your water clear (chemistry is the other half). Here is how the three filter types compare and how to keep whichever one you have working well.
Sand Filters
Water passes through a tank of special filter sand that traps debris. The workhorse of the industry: simple, durable, and cheap to run. Filters down to about 20 to 40 microns, the coarsest of the three, so water is clear but not polished.
Maintenance: Backwash when the pressure gauge reads 8 to 10 psi over clean baseline. Replace sand every 5 to 7 years.
Tradeoff: Backwashing sends hundreds of gallons down the drain, along with your chemicals and stabilizer.
Cartridge Filters
Pleated fabric cartridges catch debris down to about 10 to 15 microns, noticeably finer than sand. No backwashing at all, which saves water and keeps your chemistry stable. Popular for newer pools and required in some drought-prone areas.
Maintenance: Remove and hose off the cartridges every few weeks in season, deep clean in filter cleaner once or twice a year, replace every 2 to 3 years.
Tradeoff: Cleaning is hands-on, and replacement cartridges are a recurring cost.
DE (Diatomaceous Earth) Filters
Grids coated with DE powder filter down to 2 to 5 microns, fine enough to catch particles the other types pass. Produces the most polished, sparkling water of the three.
Maintenance: Backwash like sand, but you must recharge with fresh DE powder after each backwash. Full teardown and grid cleaning once or twice a year.
Tradeoff: The most maintenance and the most expensive to buy. DE powder requires careful handling, and some areas restrict backwashing it to the ground.
Which one should you choose?
If you are choosing for a new pool or replacing a failed filter: cartridge is the best fit for most homeowners. Fine filtration, no water waste, and the maintenance is straightforward even if it is hands-on.
Pick sand if you want the lowest-effort, most forgiving option and do not mind slightly less polish. Pick DE if you want the clearest possible water and are happy to do the extra work.
If you already have a working filter, keep it. Any of the three keeps a pool clear when it is sized right and maintained. Cloudy water with a maintained filter is almost always a chemistry problem, not a filter problem. Start with our cloudy water guide.
Filter habits that matter more than filter type
Run time: aim to turn over your full pool volume at least once a day, typically 8 or more pump hours in swim season. The best filter does nothing while the pump is off.
Watch the pressure gauge: note your clean baseline pressure. Rising pressure means a dirty filter; a reading below baseline can mean a clogged skimmer or pump basket starving the system.
Do not over-clean: a slightly dirty filter actually filters finer than a spotless one. Clean on pressure rise, not on a rigid calendar.
Keep the Chemistry Side Handled Too
A good filter plus balanced water equals a clear pool. Pool Clarity handles the water side with exact dosing from your test results. Free to use.
