Originally posted by Wanda:
Never knew there's such a thing... how does it work? Like...do u have to add chemicals or something?
The municipal water supply here is sourced from underground aquifers and contains rather high concentrations of minerals such as calcium and magnesium, i.e., the water is 'hard.'
Hard water is problematic in that it can form constrictive mineral deposits inside plumbing, eventually resulting in reduced water flow. Hard water also prevents soaps and detergents from lathering properly, and it also leaves white, crusty deposits on dishes and utensils that are allowed to air-dry after being washed.
A water softener works by passing the incoming hard water through a tank containing a bed of special resins laced with sodium ions. As the hard water flows through, some kind of chemical reaction takes place which results in the sodium ions trading places with the calcium and magnesium ions in the water. This 'softened' (and very slightly salty) water then flows into the plumbing of the house for general use.
As the sodium ions in the resin beds are depleted, the system loses its ability to soften the water, and has to be 'regenerated.' Regeneration is accomplished by pumping a highly concentrated brine (salt) solution through the resin tank. This reverses the chemical reaction used to soften the water, resulting in the accumulated calcium and magnesium ions being flushed out, and the resin beds being 'recharged' with a fresh supply of sodium ions.
The time between regenerations usually depends on the capacity of the system; given the same amount of water consumption, a system with a larger resin tank can go longer between regenerations. The regeneration process itself takes several hours, and is usually automatically scheduled to occur during periods of non-peak water consumption, for example, in the early hours of the morning. Older systems regenerate at fixed time intervals; newer ones, like mine, regenerate based on water consumption.
The only recurring maintenance that has to be performed on a typical household water softening system is to ensure that the brine tank is kept filled with an adequate supply of salt. It's a small price to pay, as a 50 lb. bag of water softening salt (really just regular salt formed into conveniently-sized briquettes) typically only costs around $5.