The answer
Water softeners (cation exchange) specifically target dissolved calcium/magnesium to stop plumbing and appliance limescale; they do not remove chemicals or bacteria. Filtration systems (carbon, RO) remove chlorine, VOCs, lead, and PFAS for taste and health safety. If hardness > 7 GPG (120 mg/L), install a softener. Pair with NSF/ANSI 42, 53, or 58 certified filters for water purity.
Sources
This answer is drawn from the standards and guidance below. It is general information about how these systems work — not a diagnosis of your property.