Sand filters are used in the filtration of contaminates and particulate from swimming pool water, with the sand acting as the filter medium.
What is a swimming pool Sand Filter?
Sand filters are used in purification of water, with a special sand used as the filter medium. As water is pumped through the sand filter, contaminates from the pool are caught between the sand particles, preventing reintroduction back into the pool water. The buildup of contaminates in the sand filter is occasionally backwashed, cleaning the sand filter and restoring the filtering ability.
There are three key types of sand filters; gravity filters, up-flow filters and slow sand filters. Gravity and up-flow sand filters both require a flocculant chemical for them to function well, as the flocculant increases the size of the contaminates which the sand filter can then effectively filter out. Slow sand filters are used to produce filtered water without or with minimal chemical use.
Sand filters are durable, reliable, and operate on simple concepts. They are usually installed in the pool water lines immediately after the pool pump, but before a pool heater or other pool equipment. As the sand wears over time, the sand inside the filter needs to be replaced every two-five years, depending on how much the filter is used, and amount and type of contaminates filtered, and how often backwashing has occurred. The act of backwashing itself can degrade the sand, so backwashing is only recommended only when needed. Pool owners that require finer particulate that can be filtered through a sand filter should consider installing a Diatomic Earth (DE) filter.