- As water is allowed to sit in a pool, over time, debris such as sand and leaves can start to build up in the water. This can affect the color and overall cleanliness of the pool. However, with a pool filter, debris is constantly being skimmed out of the water, leaving a much cleaner-looking pool, as well as creating a much more enjoyable swimming experience. There are three main types of pool filters: sand, cartridge and diatomaceous earth.
- Sand filters filter the water using specially graded sand. Water is continuously pumped out of the pool through a diffuser and into a filter tank. As the water is pumped through the tank, it is forced through the sand, leaving the debris trapped in the sand. The water is then collected at the bottom, goes through the laterals and is transported back to the pool. This type of filter can screen out debris as small as 40 to 45 microns.
- Cartridge filters use paper instead of sand to filter out debris. The process is similar to sand filtration. The water is pumped into the filtration unit through a diffuser. The water is forced through the paper filter, and the debris is left trapped in the filter. The filter needs to be cleaned or changed more often, but a cartridge filter screens out the same number of microns worth of debris that a sand filter is capable of.
- Diatomaceous earth (DE) filters are the most expensive filters, but they also screen out a greater amount of debris from pools than both sand or cartridge filters do. In a DE filter are grids covered in plastic fabric. Covering these grids is a powder called diatomaceous earth. The diatomaceous earth acts the same way that sand does in a sand filter. The water passes through the DE, and any debris is trapped while the clean water is left to pass through. However, since diatomaceous earth is much finer than sand, it can filter debris as small as five microns from the water before passing it to the laterals to be introduced back into the pool.
