The short answer
About 8 mg/L of sodium for each grain per gallon of hardness removed (NDSU Extension); potassium chloride avoids added sodium.
The numbers
NDSU Extension: 'For every grain of hardness removed from water, about 8 mg/1 (ppm) of sodium is added.' Penn State gives 7.5 mg per quart per gpg.
| Hardness removed | About |
|---|---|
| 5 gpg | 40 mg/L |
| 10 gpg | 80 mg/L |
| 20 gpg | 160 mg/L |
Potassium chloride
Potassium chloride regenerates the softener without adding sodium; makers often call for a higher setting. Options: Morton F114980000G 40 lb Potassium Chloride Softener Pellets, Compass Minerals 38240 40 lb Potassium Chloride Softener Pellets.
A drinking tap
Some households leave the kitchen cold tap unsoftened or use a separate drinking-water system.
Products mentioned
Questions readers ask
Is softened water high in sodium?
It adds about 8 mg/L per grain of hardness removed; 15 gpg water gains about 120 mg/L.
Can I drink softened water?
Many people do; those limiting sodium can use potassium chloride or an unsoftened drinking tap. Ask your doctor about your diet.