Filtration on an above ground pool is just as important as the chemicals you add to the water.  Without the proper filtration you will be fighting a never ending battle with algae.  There are three different types of filters available for Swimming Pools; DE (diatomaceous earth), Cartridge and Sand.  Most pool owners have a certain kind they like better.  I have actually used all three at different times and in different pools.  I am going to just give you a brief summary on each one so you will be able to decide which one is right for you.

DE (diatomaceous earth) - DE provides the best water filtration, however, it is more expensive and harder to maintain than a cartridge or sand filter. A DE filter will filter the water down to 3-5 micron. How does it work?  DE is added to the filter tank through the skimmer.  Inside the filter tank are grids that are coated with DE.  The water comes into the tank, flows through the grids that will capture debris and then flows back into the pool.  When the pressure gauge reaches 10 psi over the starting psi you will need to backwash the filter.  After backwashing you need to add more DE to the filter.  Once or twice a year you need to break the whole tank down and give the grids a good cleaning and make sure all the debris is out of the tank.    

Cartridge – A cartridge filter has excellent filtration along with the least amount of energy absorption of the three available.  This filter is more of a hassle to clean.  A cartridge filter works best if it is oversized for the pool.  Most companies under size the cartridge leading to very unhappy pool owners. A cartridge filter will filter the water down to 5-10 microns.  How does this work?  A cartridge is placed in the filter tank, water flows into the tank and through the cartridge and then back into your pool.  A cartridge filter is dirty when the pressure gauge reaches 10 -12 psi higher than the starting psi and you need to take the cartridge out of the filter tank and give it a really good chemical cleaning.  How often it needs to be cleaned depends on the sizing of the cartridge.  If sized properly (oversized) you should get away with cleaning it once a month.

Sand – A sand filter is by far the easiest filter for a homeowner to maintain, however, it is also the least effective way to filter the water.   A sand filter will filter the water down to 20-25 microns.  How does it work?  Sand comes into the filter is forced through the sand and then back out into the pool.  When the pressure gauge reaches 10-15 psi higher than the starting psi the filter needs to be back washed – a homeowner usually has to backwash about once a month.  Sand should be cleaned about once every other month during a backwash.  The actual sand lasts about 5 years and then needs to be changed.

Here in Eastern North Carolina sand is by far the most popular form of filtration followed by cartridge and then DE.  If you want to “go green” and have the most energy efficient filter, then cartridge is the way to go.  Remember as long as you take care of your water chemistry and have the proper filtration you should have “perfectly balanced water”!