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Swimming Pool Filter Systems Comparison Guide

Customers often ask us, what pool filter makes the most sense for my swimming pool? To answer this we need to consider local weather and personal preferences. For example, do you live in a windy, dusty climate, creating dirt in your pool or an environment with little or no debris?


Sand Filter:

Sand filters are exactly what they sound like. Sand Filters consist of large tanks filled with sand. The water gets pushed through the sand which filters out any contaminants before they end up in your pool, thus clarifying your water. Sand Filters remove particles as low as 20 microns which become caught within the grains of sand. Eventually the particles will block more and more water, raising the pressure in the filter. This will cause your filtration system to backwash or flush out the system by reversing the water throughout the filter.

Pros:

  • Easy maintenance
  • Cheap to replace
  • Sand lasts 7 years

Cons:

  • Requires backwashing (almost weekly)
  • Wastes water through backwashing
  • Filters down to 20-25 microns
  • Creates the most pressure, making it less energy efficient
  • Some local codes can restrict backwashing

Cartridge Filter:

Cartridge Filters are energy efficient, cost effective, and readily available. They consist of a filter cartridge which sits in a tank smaller than that of a sand filter and filters water through the large surface area of the filter. The cartridge’s clarity lands in the middle, filtering down to 5 microns which are picked up through the paper-like material within the cartridge. Because the filter has a large surface area it creates the least resistance and works the best under lower speeds. The cartridge filter can be taken out and sprayed down with a hose for cleaning and doesn’t require backwashing.

Pros:

  • No backwashing
  • Filters good at lower speeds for energy efficiency
  • Greater surface area
  • Traps particles as small as 5-10 microns
  • Saves water
  • Most Economical
  • Cartridges are readily available and affordable

Cons:

  • More maintenance than sand filters
  • Cartridges need to be replaced more often (every three years or so)
  • Have to clean the cartridges once or twice a season

D.E. Filter:

D.E. or Diatomaceous Earth Filters use mined fossilized exoskeletons of tiny diatoms to filter out particles. The D.E. Filter consists of a tank with a grids inside coated with D.E. Powder. The D.E. Powder acts like sand catching particles but on a much smaller scale. It catches particles as small as 3 microns, giving the clearest water out of the three filters, but not without a higher price. The D.E. Filters have a little pricier upkeep than Sand or Cartridge Filters, requiring you to replace D.E. Powder every time you have to backwash the filter. You can do this easily by adding D.E. Powder to your skimmer but you will have to give the filter a thorough cleaning once a year.

Pros:

  • Filters particles as small as 5-10 microns
  • D.E. can be added through your skimmer

Cons:

  • Higher maintenance costs
  • Costly
  • D.E. Powder is carcinogenic in it’s powder form
  • Grids need to be cleaned once a year
  • Higher resistance than cartridge filters
  • Some local codes can restrict backwashing

Which is Best?

In terms of overall performance our pick goes to the Cartridge Filter. The Cartridge Filter allows for an energy efficient, cost effective system, that still provides you with clear water. It does this by having a large surface area which allows for great filtration while being able to allow pump speeds to remain low. The lower the speed, the lower the pressure and friction in the lines, thus decreasing the amount of energy consumed by your pump. Cartridge filters, in some cases, require an additional cleaning in the pool season but we think it’s worth the efficiency.

Although we have chosen a cartridge filter for the overall choice there are still going to be people who prefer the clearest water available (D.E.) or the system with the least amount of maintenance (Sand). It all depends on what your needs are based on, the environment the pool is located in, and your preferred level of maintenance. Either way you want to make sure that your pool and equipment fit the size and characteristics of the filter you chose or it can turn out to be more work than you might have bargained for.

If you have any questions about filters or your pool system in general leave a comment below or give one of our knowledgeable staff members a shout. We’d love to help you out.

  • laury

    don’t agree with your recommendation. I had a DE system for over 15 years it worked great and i thought was economical to maintain. I changed out the whole system including pump, filter, and controls 3 years ago with cartridge based on recommendations like yours. What you didn’t mention is that cartridges only last about 3years before needing replacement. Cost of new cartridges are about 60% – 70% thw cost of the filter system. The only cost for DE is the DE material which is cheap. The filter panels last 10-15years.

  • Bill Germann

    I am replace a 48sq ft DE, the pool is app.34,000 gals.What size DE filter should I Buy?

    • PoolSupplyWorld

      Hi Bill, for your 34,000 gallon pool, the minimum flow rate to filter your entire pool in the recommended 8-10 hours is between 57 and 70 gallons per minute. A 48 square foot D.E. filter has an optimal flow rate of 72 GPM, therefore, and since you are replacing a filter of the same size, a 48 square foot filter, such as the Pentair FNS Plus Fiberglass FNSP48 D.E. Pool Filter, should be a good replacement option.

      That said, over-sizing your filter can help alleviate stress on the equipment, extend time between backwashings and also prolong the life of the filter. Thus, a 60 square foot filter, like the Pentair FNS Plus Fiberglass FNSP60 D.E. Pool Filter, would also be a good option for your size pool. For either of these Pentair filters, you would also need the proper valve, which would be Pentair Multiport Valve Kit 2″ Threaded. If you have further questions or would like immediate assistance, please feel free to contact us.