Pool filters: sand vs cartridge vs DE (2026)

Quick comparison

Filter	Micron rating	Upfront cost	Maintenance	Water waste
Sand	20	$300 to $700	Backwash every 2 to 4 weeks	High
Cartridge	10	$400 to $900	Rinse every 4 to 6 weeks, soak yearly	Low
DE	3	$600 to $1,200	Backwash plus add DE every 4 weeks	High

Sand filter

The classic. A tank of #20 silica sand catches debris as water passes through. Easy to maintain, no media to buy for 5 to 7 years.

Pros: Cheapest upfront, simple, durable
Cons: Filters only down to 20 microns (worst clarity), wastes water on backwash, sand needs replacing every 5 to 7 years

Best for: large pools, pools with heavy debris (trees), owners who want minimum hands-on time and accept slightly less clarity.

A glass-bead media swap (Zeobest, FiberClear) drops the micron rating into cartridge territory without changing the filter.

Cartridge filter

A pleated cartridge inside a tank traps debris. No backwashing. When the pressure climbs, you pull the cartridge and hose it off.

Pros: Best balance of clarity and water waste, no backwashing, simple
Cons: Cartridges cost $80 to $200 to replace every 2 to 4 years, hose-off is a 15-minute job

Best for: most modern residential pools. The default in new builds.

DE (diatomaceous earth) filter

DE powder coats grids inside a tank. Catches the finest particles of any filter type.

Pros: Crystal clear water, gets down to 3 microns, can polish algae out
Cons: Most expensive, most maintenance, DE powder must be added after every backwash, annual teardown for cleaning, DE handling has health warnings

Best for: owners who want gallery clarity and do not mind the extra work.

Sizing matters more than type

A correctly sized filter beats a fancier undersized one every time. Aim for at least 1 sqft of filter area per 10,000 gallons of pool. Bigger filter = longer time between cleanings = clearer water.

Pressure gauge is your dashboard

Note your clean pressure at startup. When it climbs 8 to 10 psi above clean, time to clean. Do not wait until flow drops at the returns.

When to call a pro

Call when you have replaced the cartridge and pressure is still high, when you have backwashed and flow is still low, or when the filter tank itself is leaking from the body (not a fitting). A cracked tank is replace, not repair.

Frequently asked questions

Which pool filter is best for a residential pool?

For most owners, a properly sized cartridge filter. Best clarity-to-effort ratio, no water waste, and no daily decisions. Sand is fine if you want minimum work and accept slightly hazier water.

How often do I replace pool filter media?

Sand: every 5 to 7 years. Cartridges: every 2 to 4 years (or sooner if pleats collapse). DE grids: every 4 to 8 years.

Can I switch filter types?

Yes, but you have to swap the whole filter, not just the media. Plumbing usually transfers fine. Plan a half-day install or $300 to $500 in labor.

What is the pressure gauge supposed to read?

Whatever the gauge reads with a clean filter and the pump running normally is your baseline. Could be 10 psi, could be 22 psi. Clean when it climbs 8 to 10 psi over that baseline.

Is DE bad for my health?

Pool-grade DE is safe for the pool. Inhaling the dry powder is bad for your lungs. Wear a mask when adding it and never let it sit dry in the air.

Can I use a clarifier in any filter?

Yes. Liquid clarifiers work in sand, cartridge, and DE. They make particles stick together so the filter catches them. Do not overdose, you can gum up cartridges.

How long should a backwash take?

Sand: 2 to 3 minutes or until the sight glass runs clear. DE: 3 to 5 minutes plus refresh the DE coating. Long backwashes waste water and pull sand out of the bed.

Pool filter types: sand vs cartridge vs DE compared