Above Ground Pool Filters - Choose Between Cartridge, Sand And De Filters

Swimming pool filters are absolutely essential for keeping pool water clear and clean. By removing debris and contaminants from the water, filters help to make your pool a pleasant and healthy environment for swimming. If you own an above ground swimming pool, there are three main types of above ground pool filters that can be used to maintain the cleanliness of your pool's water -- sand filters, cartridge filters and diatomaceous earth (DE) filters. Each type of filter works in its own way and has its own advantages. In order to decide which type of pool filter will be the best for your above ground swimming pool, it's important to understand the design as well as the pros and cons of each category.

All pool filters for above ground swimming pools serve the same purpose but in a slightly different way. Ultimately, however, the main function of swimming pool filters is to remove dirt, debris and microorganisms from the pool water. This is achieved with the help of a swimming pool pump, which forces the water from the pool to the filter where the contaminants are trapped. While this describes the basic function of all above ground pool filters, sand pool filters, cartridge pool filters and DE pool filters differ in the type of media used to remove contaminants from the water.

Sand pool filters, for instance, use a sand-filled pressure vessel to remove contaminants. Typically, these vessels will contain a series of chambers, each one with a bed of special sand referred to as pool grade #20 silica sand. The particles of this special type of sand have sharp edges which separate contaminant particles, thereby promoting filtration. As water passes through the top layer of sand, dirt and other debris are trapped by the sand while the clean water is allowed to continue on and exit through the bottom layer.

As time goes on, the sand will become clogged by the trapped dirt and debris, causing the vessel's pressure to rise as it becomes more and more difficult for water to pass through. When this occurs, sand pool filters should be backwashed, which simply involves reversing the water flow so the dirt can be knocked out of the filter and sent to the waste line. Generally, backwashing will need to be performed every few weeks in order to keep your sand filter working efficiently and effectively.

In contrast to sand pool filters, cartridge filters use cartridge elements to remove contaminants from water, just as their name suggests. These cartridge elements are often constructed from reinforced polyester and are reusable. As the pool pump propels water through a cartridge filter, the surface of the cartridge element screens out dirt and other unwanted particles. Like sand filters, cartridge pool filters will eventually come clogged. However, they are easily removable and can be cleaned simply by pressure washing with a garden hose.

DE filters constitute the third category of above ground pool filters and use diatomaceous earth to keep water brilliantly clean. Diatomaceous earth is a naturally occurring, mined substance comprised of the fossilized exoskeletons of diatoms. A porous powder, DE is used to coat grids found inside the filter housing, creating a sieve effect. As water flows through the powder-coated grids, dirt, dust, algae and microorganisms are trapped by the DE and prevented from moving on through the filtration system with the water. Similar to sand filters, DE pool filters need to be cleaned every so often either by backwashing or by draining the clogged DE to the pool's waste line and then recharging the filter with fresh DE.

Depending upon the type of media used, and therefore the type of filter used, you will experience different pros and cons. To begin with, the different types of swimming pool filters do not filter out debris and contaminants with the same effectiveness. For example, sand pool filters will trap and remove debris as small as 20 to 40 microns in size. However, cartridge filters will trap debris as small as 10 to 15 microns while DE pool filters will filter out debris particles as small as 2 to 5 microns. Obviously this means that DE pool filters are the most effective at removing contaminants from above ground swimming pools.

Of course, the various types of pool filters for above ground swimming pools also differ with respect to the ease of maintenance. As cartridge filters have a greater surface area than sand and DE pool filters, they become clogged less often. Also, many pool owners enjoy the fact that cartridge filters can be cleaned in a matter of seconds simply by washing them down with a hose. Another great advantage of cartridge swimming pool filters is that they operate at a lower pressure than sand and DE filters, which means that they exert less back pressure on the pump.

While there are many differences between the various available above ground pool filters, all three types of filters will help you to keep your swimming pool sparkling clean and clear. By familiarizing yourself with the advantages and disadvantages of each filter category, however, you can choose the type of filter that will best suit your swimming pool as well as your particular pool maintenance routine.