Aside from all of the different brands, in general there are three main types of pool filters: Diatomaceous earth (DE), sand, and cartridge filters. Sand pool filters are by far the most common type of swimming pool filters because they are easy to use and maintain. Water flows into the sand pool filter, where it’s then pressed through a bed of sand media. The tiny grains of sand filter out particles from your water, and the cleaned water flows back into your pool.This type of filter can be cleaned by regularly backwashing the sand. Backwashing refers to running the water through in reverse to remove old particulate. Backwashing can be inefficient at times due to water loss, but Pool Express offers sand filters that are equipped with new, energy efficient technology. The result is less backwashing, less water loss and energy saved. If the sand becomes exceptionally dirty, it can be replaced at little cost. These filters trap all of the fine dust, dirt and particles that pass through the skimmer basket and the hair and lint pot.