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Learn More About Filters

Types of Pool Filters

In order to make your pool easy to maintain and not a chore, it is very important to have the proper filtration system.  If you have the wrong size or do not have the pump running often enough, your pool will not stay clear and you will be constantly working on it instead of enjoying it.  At the Wet Spot, we believe that pools should be fun not work.  We believe that with just a little information, you’ll have no problem keeping it that way.  There are 3 types of filters used to maintain clarity in the water of your pool.  They are Sand, Cartridge, and DE Filters.  Here is a brief description of each type and our recommendations for your pool. 

The most common and cost effective type of filter is sand filters.  These are use in a variety of circumstances including residential pools, commercial pools, water parks, zoo exhibits, and large aquariums.  The largest filters of this size can use up to 3000lbs of sand however; the residential versions typically use 50lbs to 300lbs.  The type of sand used is silica sand.  Silica sand is used to make glass and has very sharp microscopic edges which work well to filter contaminants out of water.  The filter tank houses the sand and the dirty pool water is force through the sand bed and the clean water returns to the pool.  When the filter becomes clogged, it can simply be “backwashed” or cleaned without having to dismantle filter or disconnect hoses. The filter comes with a multiport valve to allow the water flow to be reversed which washes the debris off the sand and gets it ready to clean the pool again.  The sand stays in the filter after backwashing and the whole cleaning process only takes a few minutes.  Sand is very inexpensive and depending on filter size and chemicals used, will last for up to 3 years.  Since the filters are so easy to use and economical, we recommend them for all above ground pools and smaller in ground pools.

Another effective pool filter is the cartridge filter.  This type of filter uses up to 4 cartridges with a fabric media that can filter debris from pool water down to 20 microns.  In very rare circumstances, some cities require filters that backwash to do so into your home sewer system instead of on the ground.  This type of filter does not backwash and therefore will pass any city requirements without the need of a plumber.  These filters, for permanent pools, come in a variety of sizes from 50 sqft to 425 sqft.  The size that would be needed is based off the size of the pool and how often you want to clean it.  If you need to have this type of filter for your above ground pools, we recommend a 150 sqft filter.   The downfall of this type of filter is that the filter must be taken apart to clean it and the cartridge/s must be replaced when they wear out.  The cost of the replacement cartridges vary greatly but often range from $30 to $150 each.  This type of filter is used with most of the disposable blue pop up pools in a very inadequate size of only 8 sqft.  A lot of people get discouraged with these types of pools because they are difficult to maintain.  In actuality, if these pools had a properly sized filter, they would be easy to maintain.  This would also make them nearly as expensive as a permanent above ground pool and make the permanent pool a better buy.  As stated above, we recommend sand filters for all above ground pools; however, if you have city requirements restricting their use, this is a suitable replacement.

The 3rd most common type of filter is the DE or Diatomaceous Earth filter.  These filters are the most effective at removing debris from the water as they can filter down to 4 microns.  The most common DE filters have 2” or 2 ½” internals and therefore can handle a much greater water flow.  This makes this type of filter the preferred choice for larger in-ground pools.  These filters are similar to a cartridge filter and sand filter combined.  Like a cartridge filter, these filters have elements, called grids, inside of them.  The difference is that these grids must be coated with a fine white powder called DE.  There have been many types of DE filters but most of them have 8 grids in them.  Like sand, DE has very sharp edges to filter with, except it is much finer.  These filters also have valves to “backwash” the filter when it becomes dirty and therefore may be required to be connected to your home sewer drain.  Unlike sand, a DE filter typically only needs 3-6lbs of the powder to filter the pool.  When the filter is backwashed, this powder is removed from the system and has to be replaced.   Unfortunately, not all of the DE powder is removed by backwashing and therefore the filter must be dismantled and physically cleaned about 2-3 times per year.  Also, the grids do wear out and allow the DE to get back into the pool.  The cost of each grid ranges from $20 to $50.  Once again, these filters are the most effective at removing contaminants from the water; however, the cost of the DE powder and replacement of the grids also make it the most expensive.  In Large inground pools, we definitely recommend this type of filter.  On above ground pools, the benefits usually do not outweigh the cost difference.

All three of these filters are effective for pool maintenance and are routinely used throughout the residential pool industry.  Especially for new pool owners, sand filters are a really easy and economical system to use.  That is why we include them with our above ground pool packages.  We have all three filter types in stock and ready for you.  Let us know if you have any other questions.