Soft Water – Important Health Advice on the Effects of Softening Water
Softening water is often very helpful as it has a number of benefits, in particular reducing scale build-up and sometimes improving the taste. However, softening it also has a certain effects on human health and also on the environment which are important to consider.
The hard water to be treated passes through a bed of the resin which contains sodium and potassium ions. As the water passes through the resin, the hardness ions are trapped in the resin and replaced by the sodium or potassium ions which are released into the water – effectively softening it. The harder the water is, the more sodium or potassium ions are released from the resin and into the water.
Effect on Humans
For people on a low-sodium diet, the increase in sodium levels (for systems releasing sodium) in the water can be significant, especially when treating very hard water. A paper by Kansas State University gives an example: “A person who drinks two liters (2L) of softened, extremely hard water (assume 30 gpg) will consume about 480 mg more sodium (2L x 30 gpg x 8 mg/L/gpg = 480 mg), than if unsoftened water is consumed.” This is a significant amount, as they state: “The American Heart Association (AHA) suggests that the 3 percent of the population who must follow a severe, salt-restricted diet should not consume more than 500 mg of sodium a day. AHA suggests that no more than 10 percent of this sodium intake should come from water. The draft guideline of 20 mg/L for water protects people who are most susceptible.”
