Water conditioning systems soften “hard” water through ion exchange in a brine (very salty) medium. A softener exchanges dissolved minerals for sodium atoms, typically near the water-service entry in a large tank holding rock salt.
Public-drinking water supplies in the U.S. are free of many contaminants that threaten health. However, minerals such as calcium, iron and manganese – which are commonplace in many parts of the U.S. – aren’t considered health hazards, so water-works operators don’t remove them from community supplies.
Water conditioners come in two major categories: Agents, which are typically added to water to reduce hardness at the point of use, and devices, most of which are permanently installed components of a home plumbing system.
Agents are “active” water softening substances most commonly added to laundry water. Two commonly used hardness reducers are sodium borate (borax) and sodium bicarbonate (baking soda). These chemicals work by capturing and isolating dissolved minerals that can then be easily rinsed away. When in suspension, these minerals can't form soap curd that reduces the effectiveness of detergent.
Most devices, apart from maintenance, operate passively. The user doesn’t need to do anything to benefit from their operation. They’re a permanent part of the plumbing system – softened water flows out of every tap and outlet full time.
Softened water improves the effectiveness of soaps in bathing and cleaning, and greatly reduces the formation of mineral scale and soap scum in sinks, bathtubs and showers.
However, because they take out dissolved minerals and replace them with sodium, softeners may be problematic for people on sodium-restricted diets. In such cases, two-stage treatment is recommended – a water softener, followed by a reverse-osmosis filter designed to trap sodium.
A softening system also requires periodic maintenance to remain effective. You must add rock salt to the brine tank periodically, and the softening system needs to be back-flushed occasionally to remove trapped mineral particles. Automatic back flushing releases salt-laden brine, which has prompted some sanitary districts to ban their use. Brine may also impair home septic systems.
The Healthy House Institute (HHI), a for-profit educational LLC, provides the information on HealthyHouseInstitute.com as a free service to the public. The intent is to disseminate accurate, verified and science-based information on creating healthy home environments.
While an effort is made to ensure the quality of the content and credibility of sources listed on this site, HHI provides no warranty - expressed or implied - and assumes no legal liability for the accuracy, completeness, or usefulness of any information, product or process disclosed on or in conjunction with the site. The views and opinions of the authors or originators expressed herein do not necessarily state or reflect those of HHI: its principals, executives, Board members, advisors or affiliates.
