The hardness setting to enter on your softener, by city
Your softener's control valve asks for one number: how hard your water is. Here is that number for each Valley city we cover, and how to put it in.
Softener settings for Valley cities
The "Softener dial setting" column is the number to enter on your softener.
| City or area | How hard | Range (grains per gallon) | Softener dial setting | Source |
|---|---|---|---|---|
| Phoenix | Very hard | 10 to 17.6 | 14 | City of Phoenix Water Services Department, annual water quality report, 2025 |
| Scottsdale, south of Indian School Rd | Very hard | 13 to 15 | 14 | Scottsdale Water (City of Scottsdale), annual water quality report, 2026 (2025 data) |
| Scottsdale, Indian School to Chaparral Rd | Very hard | 13 to 17 | 15 | Scottsdale Water (City of Scottsdale), annual water quality report, 2026 (2025 data) |
| Scottsdale, north of Chaparral Rd | Very hard | 13 to 17 | 15 | Scottsdale Water (City of Scottsdale), annual water quality report, 2026 (2025 data) |
| Mesa, City Zone | Very hard | about 12 | 12 | City of Mesa Water Resources Department, annual water quality report, 2025 |
| Mesa, Eastern and Southern Zones | Very hard | about 16 | 16 | City of Mesa Water Resources Department, annual water quality report, 2025 |
| Chandler | Very hard | 5 to 20, average 16.5 | 17 | City of Chandler, water quality questions and answers, undated web page |
| Peoria | Very hard | 5.1 to 19.7 | 13 | City of Peoria Water Services Department, hardness study, 2020 |
| Gilbert | Very hard | 6.6 to 17.5, average 10.8 | 11 | Town of Gilbert Public Works (Water), annual water quality report, 2026 (2025 data) |
| Glendale | Very hard | 5.4 to 18.5, average 13.8 | 14 | City of Glendale Water Services Department, annual water quality report, 2026 (2025 data) |
| Tempe | Very hard | 10.4 to 32.6, average 12.3 | 13 | City of Tempe Water Utilities, annual water quality report, 2026 (2025 data) |
| Surprise, Mountain Vista | Moderately hard | 2.7 to 4.9, average 3.9 | 4 | City of Surprise Water Resource Management, annual water quality report, 2026 (2025 data) |
| Surprise, Desert Oasis | Moderately hard | 2.6 to 11.1, average 6.2 | 7 | City of Surprise Water Resource Management, annual water quality report, 2026 (2025 data) |
| Surprise, Surprise Foothills | Moderately hard | 5.1 to 5.6, average 5.3 | 6 | City of Surprise Water Resource Management, annual water quality report, 2026 (2025 data) |
| Surprise, Circle City | Hard | about 8.2 | 9 | City of Surprise Water Resource Management, annual water quality report, 2026 (2025 data) |
| Queen Creek | Very hard | 6 to 17 | 12 | Town of Queen Creek Water Services, water quality questions and answers, undated web page |
| Fountain Hills | Very hard | about 16 | 16 | EPCOR Water Arizona (Chaparral City water system), annual water quality report, 2025 (hardness sampled in 2024) |
How to change the setting
Most softeners have a control head on top of the resin tank with a small screen and a few buttons. The hardness setting is usually a menu item called “hardness”, “grains” or “gpg”. Your owner’s manual gives the exact steps; many manuals are on the manufacturer’s website if you have lost yours. On older dial models, the setting is a numbered wheel.
Setting it too low or too high
- Too low: the softener thinks your water is softer than it is, so it waits too long to recharge. Hard water slips through for the last days of each cycle, and scale comes back.
- Too high: it recharges early, and every recharge uses salt and sends water down the drain.
Moved house, or the factory default?
Softeners often leave the factory, or a previous owner, set to a number that has nothing to do with your water. If you have just moved to the Valley, or within it (Mesa’s zones differ by 4 grains per gallon), check the setting.
When to test instead
Peoria’s 48 test sites ranged from 5.1 to 19.7 grains per gallon and Chandler gives 5 to 20 for the city. In cities with ranges that wide, a home test kit gives a better setting than the city figure.
Common questions
- What should my water softener be set at in Arizona?
- There is no single Arizona number. Most Valley cities publish figures from about 11 to about 17 grains per gallon, and Surprise's systems about 4 to 8; use your own city's figure, rounded up, or your own test result.
- Is it bad to set a water softener too high?
- It is not harmful, but it is wasteful. The softener recharges before it needs to, using extra salt and water each time.
- My softener asks for ppm, not grains. What do I enter?
- Multiply the grains per gallon by 17.1. For example, 14 grains per gallon is about 240 ppm.