On-Demand Well-Water Softener
Where well water is the supply, use an on-demand softener.
Spec
Applies uniformly from Gold upward.
Scope
Dwellings on well water with measured hardness above 7 grains per gallon (gpg) or 120 mg/L as CaCO₃.
Requirements
- 01.
Install a demand-initiated regeneration (DIR) water softener — also called metered or on-demand. Time-clock-only softeners are not permitted.
- 02.
Softener must be sized to the household water-use volume and source hardness.
Documentation
Evidence the inspector / Institute will need.
- 01.
Well-water hardness test result (current within 12 months).
- 02.
Softener manufacturer spec sheet showing demand-initiated regeneration control.
- 03.
Photo of installed unit with model number and capacity rating visible.
Guidance
Why demand-initiated, not time-clock
Time-clock softeners regenerate on a fixed schedule (e.g. every 3 days) regardless of actual water use. A typical 4-person household with a time-clock softener wastes 5,000-15,000 gallons of water and 200-500 lbs of salt per year compared to a demand-initiated unit, which regenerates only after the resin bed has actually been depleted.
Twin-tank vs single-tank
Twin-tank softeners (e.g. Kinetico) provide continuous soft water during regeneration and use roughly 30% less salt + water than single-tank units. Higher upfront cost but the lowest lifetime operating cost.
Note
Potassium chloride salt is a sodium-free alternative for households with dietary sodium restrictions. Costs ~3× more than NaCl pellets but works in any DIR softener.