A review of the different types of swimming pool filters.

There are three types of pool filters: Cartridge, Diatomaceous Earth and Sand filters. In this article we discuss the differences in these pool filters.

Cartridge Filters

Cartridge filters have become the most popular type of pool filter for residential pools in the past 10 years. This is because cartridge filters provide great water clarity and require a minimum of maintenance.

In addition, cartridge filters help us to conserve our water resources. They do not waste thousands of gallons of water each year through the backwashing process, as is required for DE or sand filters. The process of cleaning a cartridge filter simply involves removing the cartridges and cleaning them with a garden hose.

• Filter Media – spun bonded polyester material
• Filtration Efficiency – 10 – 15 microns
• Cartridge Life – 3-5 years
• Cartridge Cost – $400 – 500 for a set of four
• Maintenance – clean cartridges every 6 months or sooner if the pressure reaches 10 psi above normal.
• Best Suited For – most residential pools

[If your pool is situated under HEAVY foliage and subject to algae blooms, we recommend a DE filter.]

D.E. Filters (diatomaceous earth)

D.E. filters are a popular type of pool filter for residential pools. They became very popular in the 80’s and 90’s and are still widely used today, though they are somewhat eclipsed by the emergence of large cartridge filters.

DE filters provide the finest possible filtration for a swimming pool but they are also the most expensive to maintain. DE filters also require a direct connection to the sanitary sewer for backwashing (unless you use a separation tank which we strongly advise against).

The maintenance on a DE filter involves backwashing and recharging the filter at least monthly and tearing it down and cleaning it every six months.

• Filter Media – diatomaceous earth
• Filtration Efficiency – 5-8 microns
• Grid Life – 5 years (depending on filter maintenance)
• Grid Cost – $200 – 250 for a set of eight grids
• Maintenance –
  Monthly-backwash and recharge filter once per month or sooner if pressure rises 10 psi above normal
  Every 6 months -break down and clean filter – residential pools

[If your pool is situated under HEAVY foliage and subject to algae blooms, we recommend a DE filter.]

Sand Filters

Sand filters used to be just about the only filter that was offered for pools in the early days. Originally, they were huge tanks measuring 4-5 feet in diameter, but then the industry developed the high rate sand filter we know today. These range between 24 and 36 inches in diameter.

Sand filters do not filter quite as finely as DE filters, but with proper maintenance, they can achieve really good water clarity. Sand filters are ideal for heavily used pools because they can run 24 hours per day, unlike DE filters which require a certain amount of “off” time to refresh.

• Filter Media – specially graded filter sand
• Filtration Efficiency – 10-15 microns
• Sand Life – 3-5 years on home pools, 1-2 years on heavily used pools (hotels, apartments, institutions)
• Sand Replacement Cost – $400 – 800 depending on the size of the filter and other particulars
• Maintenance – thoroughly backwash weekly or sooner
• Best Suited For – heavily used pools such as apartments, hotels and institutional pools.

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