Technically, the term “water treatment” refers to any modifications made to raw water (water from the original source, i.e. rivers, lakes, streams, etc.). Included under the umbrella term “water treatment” are both water softeners and water filters. For this reason, the functions of the two different technologies are often seen as interchangeable.

Water filters and softeners do, in fact, serve very different purposes. The main goal of a water filter is to provide clean, contaminant-free water for drinking and other purposes. The main goal of a water softener is to remove “hardening” minerals like calcium and magnesium from the water. Water softeners do not remove dangerous chemicals or bacteria. Read more

There are two major factors involved when comparing prices among the three modes of water purification. First, one must consider the energy needed to clean and filter water. Reverse osmosis, with its dependence upon high pressure to subvert the normal flow of water, requires an energy source and is fairly costly. Distillation, with its dependence upon heat to vaporize ground and surface water, also requires an energy source.

Though solar power remains an option for the required heat of distillation, it is still fairly inefficient and impractical. Carbon and multimedia water filters, whether installed at the point of water’s entry in a house or at a tap, do not require any added energy source. Water flows just as it normally would; it is merely diverted through the filter. The higher electricity costs of reverse osmosis and distillation systems double the total cost of the purified water product which carbon and multimedia filters produce. Read more

Single media filters, typically constituting carbon or sand, absorb impurities from water, through both physical and chemical processes, as the water passes through the filter cartridge.

Single media filters will generally remove undesirable tastes, colors, and odors from water as well as such chemicals as hydrogen sulfide, radon, chlorine, volatile organic compounds (VOCs), pesticides, and benzene (Ramstorp, 2003). Drinking water filters will also remove lead and other chemicals transferred from plumbing systems to water. Read more

Reverse osmosis will generally remove any molecular compounds smaller in size than water molecules. Such compounds include salt, manganese, iron, fluoride, lead, and calcium (Binnie et al, 2002). Reverse osmosis is extremely efficient at stripping minerals from water, and it is highly valued as a water purification process in the printing industry, in which mineral-free water must be used.

Although reverse osmosis supplies useful, mineral-free water for printing purposes, it does not provide the healthiest drinking water. Reverse osmosis will remove several mineral and chemical materials from water, including salt, fluoride, lead, manganese, iron, and calcium. Reverse osmosis, because it removes minerals according to physical size, is non-selective in its removal of dangerous and beneficial minerals. Read more