Water Softener Salt Dosage
Dial in your softener settings by pairing household usage, water hardness, resin size, and target efficiency to find the right salt dose and regeneration cadence.
Always follow the manufacturer manual for maximum salt settings and safety procedures when servicing your softener.
Examples
- 320 gal/day, hardness 22 gpg, 2.0 ft³ resin, efficiency 4,200 g/lb, reserve 10%, target 6 days ⇒ Regenerate every 6.2 days using 9.0 lb of salt (≈ 10.1 lb/week). Cycle hardness removed: 38,034.0 grains • Cycle meets target days.
- 420 gal/day, hardness 35 gpg, 2.5 ft³ resin, efficiency 4,000 g/lb, reserve 12%, target 7 days ⇒ Regenerate every 5.7 days using 12.6 lb of salt (≈ 15.4 lb/week). Cycle hardness removed: 50,091.6 grains • Cycle limited by resin capacity.
FAQ
How often should I adjust the settings?
Recalculate each season or whenever water usage shifts significantly (new appliances, additional occupants, or irrigation changes).
What if I use potassium chloride instead of salt?
Potassium chloride regenerates less efficiently—lower the target efficiency to 3,000–3,500 grains per pound to compensate.
Can I run beyond the recommended days?
Long stretches risk hard water breakthrough. If you need longer intervals, increase resin volume or accept a higher salt dose per regeneration.
How do I adjust for iron in the water supply?
For every ppm of iron, add 3–5 grains to the hardness input so the calculator accounts for extra resin loading before regeneration.
Additional Information
- Reserve capacity protects against unexpected guests or laundry spikes so you do not exhaust the resin before a scheduled regeneration.
- Target efficiency controls salt usage—higher grains per pound means leaner salt dosing but may shorten cycles on small tanks.
- Cycle hardness is capped at roughly 30,000 grains per cubic foot to reflect typical 8% crosslink resin ratings.
- Result units: pounds of salt per regeneration, pounds per week, and grains of hardness removed