Water softening is the act of reducing the level of magnesium and calcium ion concentration from hard water. Although the World Health Organization has found no evidence of hard water being harmful to humans, many people may still find it undesirable, mainly because soaps and detergents don’t lather well with hard water making it difficult for cleaning purposes. The best and the most used method of reducing hardness from water is to use a ion-exchange resin device, more commonly known as a water softener.
Water softener systems work by replacing the magnesium and calcium ions causing the hardness with sodium ions. The way it works is that the water passes through a negativity charges bed of resins containing sodium ions, though it can also use potassium or hydrogen ions. As the negativity charged particles absorbs and binds the magnesium and calcium ions it releases the sodium ions, thus replacing the hardness minerals with sodium. How much sodium is required for this process depends on the amount of hardness minerals in the water, the harder the water the more sodium ions is released in to the water to reduce the hardness. Such resins are also available to reduce the levels of carbonate, bi-carbonate and sulfate ions from the water, but they release hydroxyl ions in the water instead.
As these resins become filled with undesired ions from the water they slowly lose their effectiveness and needs to be recharged. This is usually done by passing a highly concentrated brain of usually sodium chloride (salt for water softener), or potassium chloride, or hydrochloric acid solution through them. This process replaces the hardness minerals from the resins with sodium or potassium.
It should be noted that too much sodium in the body can potentially cause side effects, so if you have hard water problems, it would be wise to have two taps in the house, with only one of them running through the water softener that you can use for cleaning purpose, while the other one with hard water that you can use for drinking, since the hard water has not be proven to have any adverse effect on the body for drinking. It’s once again mainly a problem for plumbing and house cleaning/washing. Other solutions include using a saltless water softener which can either use a completely different water softening system that does not include salt or it might simply be something like a kinetico water softener that instead of using salt you use potassium chloride to recharge the water softener resin.