High rate sand filters information
The method of filtration that has been in existence the longest is the sand filter. It is also the most popular type of filtration.
The high rate sand filters are usually .45 to .55 mm. The sand that is used with the filter is known as pool grade #20 silica sand. The sand filter separates the particles while allowing filtration to take place. This type of sand filtration is known as “depth” filtration because dirt is forced
through the sand bed, then trapped in small spaces between particles of sand. At first, the clean sand filter will eliminate large particles, but as the sand bed collects more dirt, it will eliminate the smaller particles as well.
When sand filters are in the filtration mode of operation, the water will always flow from the top to the bottom. Clean, filtered water is able to pass through the filter through a lateral or under drain that contains slots to hold back sand.
Cleaning is an important process of maintaining your sand filter in order for it to operate at optimum level. It is also important to extend the life of your other pool filter equipment.
The sand filter is cleaned by reversing the flow through the filter to the “waste” line. This process is known as backwashing. The filter should be cleaned on a regular basis, approximately once a month. You should carefully read your filter instructions to learn how to reverse the water flow in
order to properly clean the dirt and debris from the filter.
The sand in a crushed sand filter should be replaced every three to five years. Of course, this would depend on how often the pool is used during the season and the types of contaminants in the air that come in contact with your filter. https://waterfilter.my/