There are three basic types of pool filters. You can have a sand filter, a cartridge filter, or a DE (Diatomaceous Earth) filter. Most above ground pools are sold with sand filters, but there are these two other options that you should be aware. That awareness will help you to make an informed decision about which filter is best for your above ground pool.
Pool Filters – how do they work?
Pool Filters act as strainers for your big bowl of pool soup! They are part of the pool circulatory system, depending upon the pool pump to draw water from the pool through it’s filter element. The filter element will trap particles of dirt, debris, and even suntan and body oils from the water as it continues on it’s close looped journey to eventually be returned to the pool as part of it’s cycle. Your pool filter works similarly to a fish aquarium filter, but of course on a much smaller scale.
Swimming pool filters are only one element of the cleaning system in a swimming pool. Water quality chemical cleaners and devices such as pool vacuums are other parts of the system, as are your pool pump. It is important to realize that all of these elements are part of the healthy infrastructure of your pool.
Sand Filter System
Sand filters are regarded as the tried and true system for filtering your pool water. They are the most economical as well, lasting for between 5 and 10 years before needing a replacement. A sand filter will increase pressure resistance to flow of water through it as it goes about its very efficient filtering process. A sand filter can remove dirt pieces as small as 20 microns (that is really small!). Once the pressure increases to between 7 to 10 lbs there is enough accumulated debris trapped by the filter to initiate a backwash. Check out this Youtube video to show you the details of how to go about backwashing your sand filter.
Cartridge Filter System
A newer technology than sand filtration, the cartridge filter is akin to the cartridge filter in your hot tub. A cartridge filter can be more efficient than a sand filter by filtering out particles as small as 15 microns! A knock on them is that they don’t always seal off large particles which the find their way back into the pool. A cartridge can be removed, soaked and cleaned, and then returned to its task of filtering the above ground pool water. Cartridge filters can last between 1 and 3 years before requiring replacement.
DE Filter System
The DE filter is the most efficient and most expensive of the three systems. It can remove particles as small as 4 microns! The DE filter does not require frequent backwashes. Overall, the quality of your above ground pool water will the best when using a DE style filter.
There you have it. A quick introduction of above ground pool filters. Here is a shout – out to Wikipedia and an excellent overview of swimming pool sanitation that really help me and I would suggest as a great reference to understand the importance and nuances of swimming pool filtration and sanitation. Check it out !