Less scale.
A better-matched water system.

A softener exchanges hardness minerals to reduce scale throughout the home. Reverse osmosis uses a membrane at a dedicated tap to reduce many dissolved substances in drinking water. They solve different problems.

Sizing should account for water hardness, household use, peak flow and the desired interval between regeneration cycles. The number of people in the home is useful, but it is not enough on its own.

A softener is intended to address hardness, not every possible water-quality concern. If safety or a specific contaminant is the concern, use appropriate source information or testing and select treatment designed for that issue.

Most conventional systems need salt replenishment, periodic checks and occasional service. Actual frequency depends on the equipment, hardness setting and household water use.

A softener helps reduce new hardness-scale formation. Existing deposits may need separate cleaning, and heavily scaled plumbing or equipment may not return to its original condition simply because the incoming water is softened.