The Purative Way to Safe Bathing!
Choosing a backwashing filter can be a simple or a complex issue. You should not expect a backwashing filter to be a magic, one-step solution to any problem. Often, in fact, it is the final stage of a more complex treatment system.
Although a backwashing filter may look like a water softener and be the same size, it is altogether different. Softeners are "ion exchangers", not filters.
A backwashing filter is a water filter that cleans itself periodically by rinsing away impurities it has filtered from water.
A backwashing filter is a simple device that consists of a large tank that is filled with a filtering substance called a filter medium. (The plural is media.) Water enters the top of the tank through a special control valve and passes downward through the medium, which removes impurities and holds them. Some media do not hold impurities, but cause a change to occur. Calcite, for example, dissolves and in the process increases the pH of acidic water. The treated water then enters a tube at the bottom of the mineral tank, passes upward through the tube (called a riser), and exits the filter via the control valve.
When the filter medium is saturated with contaminants, the control valve initiates a backwash. The backwash is an operation in which water passes backward through the filter at a rapid rate. It enters the tank at the bottom via the riser tube, then passes upward through the filter medium, exiting at the top, via the control valve. The rapid upward flow, in addition to washing away stored impurities, fluffs and resettles the medium bed, preparing it for another filtering cycle.
Some media have numerous applications, like the very useful and widely used GAC, or Granular Activated Carbon, which is used to remove chlorine, the by-products of chlorination, pesticides, herbicides, and chemicals in general. GAC, following proper pretreatment, also removes iron and hydrogen sulfide. It comes in various formulations made from a variety of materials (bituminous coal, coconut shells, wood, etc.), each with its own special properties.