White scale on fixtures, spots on dishes, soap that won't lather, stiff laundry.
A measured hardness value: your utility's reported range is a starting point, a $12 strip or a lab test gives you a number for your home.
Softener sizing depends on measured hardness, household size and bathrooms — never buy on a guess.
Ion-exchange softeners address hardness itself; filters don't. Conditioners alter scale behavior with different trade-offs.
A local professional can measure hardness during a visit and quote a properly sized system.