How do I tell if I have hard water?

Common signs include white scale on faucets, spots on dishes, soap that does not lather well, stiff-feeling laundry, and mineral buildup around showerheads. You may also notice that your water heater or other appliances require frequent descaling or repairs.

These signs suggest hardness, but they do not measure its severity. A water test determines the calcium and magnesium concentration and provides the information needed to size a softener properly.