To enjoy your pool to the fullest, you need to have an effective pool filter system to remove fine particulates from the water and allows you to swim in a crystal clear pool. A good filter should be durable and effective, but perhaps you’re not sure what kind of swimming pool filter is best for your pool. There are three basic types:sand filters, which use sand as a filtration medium; cartridge filters, which use replaceable cartridges to filter the water; and DE, or diatomaceous earth filters, which can filter out particles that can get through a sand or cartridge filter. Here is a brief explanation of each type.
Sand filters use a special type of graded sand for filtration. The water enters into the filter tank through a diffuser. The water goes down through the bed of sand, and as it does this, debris is trapped by the sand while the water goes through. Once the water reaches the bottom of the sand filter, it is routed back to the pool. Sand filters have been around longer than the other types. They allow the filter to trap debris larger than 40 microns in size (one micron is one millionth of a meter). The sand filter can be cleaned by reversing the water flow through the sand using a special valve.
Cartridge filters usually produce about the same water quality as sand filters, though some experts say it filters better than sand. While cartridge filters have had a reputation as being a hassle to maintain, the design of cartridge pool filters has improved to the point that they only need to be cleaned once or twice a year. Cleaning a cartridge-type pool filter involves removing the cartridge, soaking it in tri-sodium phosphate (TSP) and rinsing it with a hose.
DE, or diatomaceous earth filters are covered with a special fabric and a plastic grid. Diatomaceous earth is a very fine powder that covers the grids and filters the water. DE filters can filter out debris as small as 5 microns in size, compared to 40 microns for sand filters. These filters are considered by some to be the best filtration system for above ground pools. The water comes out crystal clear. Though manufacturers’ instructions may vary, pre-coating the filter with diatomaceous powder is usually done by adding it through the skimmer while the filter is circulating.
