Sand is 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.

For more information about swimming pool sand filters please contact Pro Pools at 888-352-7582.