What hardness is
Hardness is calcium and magnesium carried in the water. Heat it or let it dry on a surface and the minerals drop out as scale. Labs report it in mg/L; softener sellers prefer grains per gallon. Lake-sourced regional water sits in the middle of the hardness range; private wells in the moraine region are often harder, sometimes considerably so.
Where it shows up
- Chalky rims on aerators and shower roses.
- Haze on glass shower panels.
- A crust inside the kettle.
- Sediment in the bottom of water heaters, causing rumbling and lost efficiency.
- Scale on the heat exchanger of tankless heaters.
- Soap that does not lather well.
Options
| Approach | How it works | Notes |
|---|---|---|
| Ion exchange softener | Swaps hardness minerals for sodium or potassium | Needs salt and a drain; most effective |
| Scale inhibitor cartridge | Slows scale formation | Lower maintenance, less complete |
| Point-of-use treatment | Treats water at one tap | Good for drinking water, not whole house |
Living with it
If you choose not to soften, soak aerators and shower heads in vinegar periodically, drain a few pails from the tank heater every six months, and descale tankless units on schedule.
Softeners and drinking water
Softened water contains added sodium. People on sodium-restricted diets may prefer a bypassed cold tap at the kitchen, or a potassium-based softener. Ask your doctor if unsure.
For installation, see water softener installation and water filtration systems.