Comparison
Water softener vs reverse osmosis
A softener treats hardness for the whole house. Reverse osmosis purifies drinking water, usually at one tap. They solve different problems, and many homes use both.
| Water softener | Under-sink reverse osmosis | |
|---|---|---|
| Treats | Calcium and magnesium | Dissolved solids and many contaminants |
| Where | Whole house | Usually the kitchen tap |
| Installed cost | $1,200 to $3,800 | $300 to $950 |
| Yearly cost | $50 to $150 | $50 to $250 |
Neither is the usual whole-house answer for chloramine. That takes catalytic carbon.
Sources: HomeGuide softeners, HomeGuide reverse osmosis, Angi.
These are published ranges and general guidance, not quotes. In the Bay Area, Soft Patagonian offers free water tests.
Quick answers
Do I need both a water softener and reverse osmosis?
Many homes use both. A softener handles hardness throughout the house, and reverse osmosis cleans drinking and cooking water at the kitchen tap.