Types of pool filters: which one suits your pool?

Choosing the right pool filter keeps your pool water clear, reduces algae growth, and lowers maintenance time. The three main types of swimming pool filters are sand, cartridge, and DE (diatomaceous earth). Some media filters can also use alternative media like glass or zeolite. Below, you will see how each filter type works, the micron rating it can trap, maintenance requirements, and which pools they suit best.

What are the different types of pool filters?

Most residential pools use sand, cartridge, or DE filters.

• Sand filters use a tank filled with media. Water flows through the bed and leaves dirt behind.

• Cartridge filters use pleated surface filtration to trap particles in a replaceable element.

• DE filters coat a grid with diatomaceous earth powder to catch ultra fine particles.

Typical capture ratings

• Sand: about 20 to 40 microns

• Glass media: about 10 to 20 microns

• Zeolite: about 10 to 20 microns

• Cartridge: about 10 to 20 microns

• DE: about 2 to 5 microns

A human hair is roughly 70 microns wide, which helps you visualise what each filter can remove.

How do sand pool filters work?

A sand filter is a media filter that pushes water through a bed of graded media to trap particles. Standard pool sand captures larger debris first and finer dirt as the bed loads. Many modern systems swap sand for glass media or zeolite to improve clarity without changing the tank or fittings.

Pros

• Simple, robust, and well suited to larger pools and commercial style usage

• Easy to clean with a backwash cycle

• Works with any pool surface and with saltwater chlorinators

Cons

• Uses more water during backwashing

• Higher running pressure than cartridge, which can increase pump energy

• Standard sand is less effective on fine dust than cartridge or DE

Best fit

• Medium to large pools, heavy bather loads, and owners who prefer low fuss maintenance

Maintenance

• Backwash when the pressure gauge rises about 8 to 10 kPa above clean pressure

• Rinse after backwash to reset the bed

• Replace media every 3 to 5 years for sand and every 5 to 7 years for glass or zeolite, depending on usage and water quality

How do cartridge pool filters work?

A cartridge filter uses a pleated element to trap particles on and within the media. Water passes from outside to inside the cartridge and returns to the pool. Because flow faces less resistance, cartridge systems often run at a lower pressure than sand filters.

Pros

• Captures finer particles for crystal clear water

• Lower pressure drop can improve energy efficiency

• No backwashing, which saves water

Cons

• Elements need periodic hosing and occasional soaking in cleaner

• Cartridges must be replaced when the media wears or collapses

• Not ideal for heavy debris after storms without frequent cleaning

Best fit

• Smaller pools, new pool owners who want easy maintenance, and areas with water restrictions

Maintenance

• Hose pleats from top to bottom when pressure rises or flow drops

• Soak in cartridge cleaner when oils build up

• Replace elements every 2 to 3 years on most residential pools, sooner with heavy use. For steps, see the guide for cleaning pool filter cartridges.

What is a DE pool filter?

A DE filter coats internal grids with diatomaceous earth powder, which traps very fine particles down to about 2 to 5 microns. Clarity is excellent, often the best of all types.

Pros

• Highest clarity with very fine particle capture

• Strong choice for pools where water appearance is critical

Cons

• More complex to clean and recharge with DE

• Some regions restrict DE disposal to protect waterways

• Higher maintenance effort than sand or cartridge

Best fit

• Owners who demand the clearest water and are comfortable with careful maintenance

Maintenance

• Backwash when pressure rises, then recharge with the correct amount of DE

• Periodic teardown and cleaning of the grids

Which pool filter type is best for residential pools?

Choose based on pool size, debris load, and how much time you want to spend on maintenance.

• Sand or glass media suits larger pools and busy families who prefer quick backwashing.

• Cartridge suits small to medium pools, water conscious homes, and owners who want clear water with simple element cleaning.

• DE suits premium clarity goals and owners comfortable with more hands on care.

If you run a saltwater pool, all three types can work. Most pool owners pair saltwater chlorinators with a pool filter system that includes sand or cartridge because maintenance is simpler.

What are the pros and cons of sand, cartridge, and DE filters?

Sand and media filters

• Pros: tough, easy to operate, handles heavy loads

• Cons: uses backwash water, lower fine particle capture unless upgraded to glass or zeolite

Cartridge filters

• Pros: clear water, low pressure for better energy efficiency, no backwash

• Cons: manual cleaning, element replacement cost

DE filters

• Pros: best clarity, captures the smallest particles

• Cons: most maintenance, careful waste handling, higher cost over time

Are there pool filters for above ground versus inground pools?

Yes. Smaller above ground pools often use compact cartridge filters, while inground pools commonly use larger sand or cartridge systems. Match the filter size to the pool volume and the pump’s flow rate so you achieve full turnover each day in the swimming season with a suitable filter.

Do saltwater pools need a special filter?

No. Saltwater pools do not require a special filter. Choose the filter type you prefer and ensure the tank, o-rings, and fittings are compatible with saltwater. Keep pH and calcium in range to reduce scale that can clog filters and reduce flow. If you also need a new pump, compare options in types of pool pumps.

How does water clarity differ between filter types?

DE delivers the finest clarity, cartridge follows closely, and sand trails unless upgraded media is used. That said, a well sized sand filter with glass media and correct run time can keep water clear and prevent it from becoming cloudy for most residential pools. Water clarity also depends on maintaining correct chlorine levels and balanced chemistry. For tools, browse pool test kits.

What is the easiest pool filter to maintain?

Sand and glass media filters are the easiest for most families because cleaning is a quick backwash and rinse, allowing you to spend less time on maintenance. Cartridge is also simple but needs hands on hosing. DE gives the clearest water but demands the most time.

How do I choose the right filter for my pool?

Use these quick rules to decide:

• Pool size and usage: larger pools or frequent pool parties favour sand or glass media; smaller pools often suit cartridge

• Water clarity goals: choose cartridge or DE for the best fine particle capture

• Maintenance preference: choose sand for fast backwash cleaning, cartridge if you prefer saving water

• Energy: lower pressure cartridge systems can reduce pump power and runtime

• Budget over time: factor media replacement, cartridges, and DE powder into yearly costs

With the right filter size, clean media, and proper chemistry, you will keep your pool water clean and maintain clean water that is inviting and crystal clear year round.

Conclusion

Choosing the right pool filter comes down to matching your pool size, debris load, and maintenance style. Sand and glass media filters suit larger or busier pools and offer quick backwashing. Cartridge filters excel at fine-particle clarity with simple element cleaning and no backwash. DE delivers the sharpest water but requires the most care. Size the filter correctly to your pump and turnover needs, keep media clean and chemistry balanced, and your pool will stay clear, inviting, and easier to maintain year round.