The short answer
Salt use = grains removed ÷ grains per pound of salt. Water Conditioning & Purification notes California requires efficiency-rated softeners to reach at least 4,000 grains per pound, and that efficiency falls as the salt setting rises: its example drops to about 1,867 grains per pound at a heavy setting. Three people on 15 gpg water remove about 23,600 grains a week: roughly 6 lb of salt a week at 4,000 grains per pound, or about 12 lb at a heavy setting.
By household (15 gpg, weekly)
| People | Grains a week | At 4,000 grains/lb | At about 2,000 grains/lb |
|---|---|---|---|
| 2 | 15,750 | about 4 lb | about 8 lb |
| 3 | 23,625 | about 6 lb | about 12 lb |
| 4 | 31,500 | about 8 lb | about 16 lb |
| 5 | 39,375 | about 10 lb | about 20 lb |
Cutting salt use
- Set the hardness to your test result, plus about 4 gpg per ppm of iron.
- Use a metered valve so it regenerates on gallons, not days.
- Use the lowest salt setting that keeps the water soft.
Salt we cover
Pellets: Morton 40 lb. Solar crystals: Diamond Crystal 50 lb. Potassium chloride: Morton, which may need a higher setting.
Products mentioned
Salt pellets · Morton
Morton 40 lb Softener Salt Pellets
Pellets · 40 lb
Solar salt crystals · Diamond Crystal
Diamond Crystal Solar Naturals 50 lb Solar Salt Crystals
Solar crystals · 50 lb
Potassium chloride · Morton
Morton F114980000G 40 lb Potassium Chloride Softener Pellets
Potassium chloride pellets · 40 lb
Questions readers ask
How many bags of softener salt a month?
For three people on 15 gpg water at an efficient setting, about one 40 lb bag every six or seven weeks; at a heavy setting, about one every three weeks.
Why is my softener using so much salt?
A high salt setting, a timer regenerating more often than needed, or hardness set higher than your water.