Swimming Pool Filtration Methods

Sand - the oldest and most popular method of filtration for swimming pools and spas. Water flows from top to bottom during normal filtration cycles and use an lateral system in the bottom of the filter to return water back to the pool or spa. Sand filters generally use #20 silica sand which is approximately .40 to .55 mm. As water passes from the top of the filter to the bottom particles of dirt and debris collect on top of and in the sand bed. The filter does need to be cleaned on a normal basis by simply reversing the water flow through the sand. This is usually achieved with a multi-port valve on top of or on the side of the filter.

Cartridge - is BETTER filtration than sand and provides roughly twice as file filtration than that of sand. When water passes through a cartridge filter, the dirt particles are screened out. It is important to clean the cartridges on a normal basis as accumulation of dirt on the outside of the cartridge can drastically effect the efficiency and effectiveness of the filter. Generally, for cleaning the cartridge is removed, soaked in Tri-Sodium-Phosphate then sprayed off with a hose.

D.E. (Diatomaceous Earth) - is the BEST water filtration method available for swimming pools today. Which means it removes even smaller particles than the sand and cartridge methods. Diatomaceous earth is a porous powder with microscopic openings, that when magnified looks like tiny sponges. Clean, Clear water can pass through the openings but any water with small particles ranging from 1 - 3 microns become lodged in the diatomaceous earth particles. All D.E. filters use internal elements to give the powder something to adhere to. Follow the manufacturers instructions for pre-coating a D.E. filter with diatomaceous powder. This is generally done by adding the powder through the skimmer with the filter system circulating.