Water hardness in Marana
12.6 gpg very hard
Tap water in Marana is very hard: 12.6 gpg (215 mg/L · 12 °dH · 21.5 °fH).
Source: Town of Marana Water Hardness per System (May 2026) (2026-05) · data checked 2026-10-20
Range across supply zones: 56–260 mg/L.
7 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| gpg | mg/L | ||
|---|---|---|---|
| 10-092 Picture Rocks (Continental Reserve/Picture Rocks/Cortaro and Silverbell) | 12.6 | 215 | very hard |
| 10-136 Palo Verde (Twin Peaks and Clayton) | 12.9 | 220 | very hard |
| 10-138 Airline/Lambert (Avra Valley Rd, Airline Rd, Lambert Ln, Saguaro Bloom, Silverbell Rd and Linda Vista) | 12.6 | 215 | very hard |
| 10-150 Marana Municipal (Gladden Farms, Rancho Marana, Honea Heights, Yoem Pueblo, Marana Main Street, Tangerine) | 8.5 | 145 | hard |
| 10-150 Marana Municipal (San Lucas, Warfield Circle, Amole Circle) | 6.4 | 110 | moderately hard |
| 10-329 Hartman Vistas (Hartman Vistas, Hartman 10, Oasis Hills, Oshrin Park, Cortaro Peaks and I-10) | 4.4 | 76 | moderately hard |
| 10-406 Airport (Marana Regional Airport) | 14.3 | 245 | very hard |
The Town of Marana publishes hardness per water system as of May 2026. Values across its 7 systems run from 56 to 260 mg/L (3.3 to 15.2 gpg), and 215 mg/L (12.6 gpg) is the median we show. Your address decides which system you are on, so look up the town's table for your own neighborhood before choosing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 12.6 gpg |
|---|---|
| Utility | Town of Marana Water and Water Reclamation |
How Marana compares
- Tap water in Marana is 39 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 477 of 1372 in the United States (1 = hardest); 65 % of these cities have softer water.
- In Arizona it is number 7 of 12 cities; the regional median is 13 gpg.
- Nearest city with clearly harder water: Mesa, 123 km away (16 gpg).
Ranking of the hardest and softest water in the United States →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Marana
| Brand | Setting for this water |
|---|---|
| Bosch | H03 |
| Miele | 12 °dH |
| AEG / Electrolux | 3 |
| Beko | 3rd |
| Hoover | S2 |
| LG | H2 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is Marana water hard or soft?
It is very hard: 215 mg/L as CaCO₃ (12.6 gpg, 12 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Marana safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
How many grains per gallon is Marana water?
12.6 gpg, equal to 12 °dH, 21.5 °fH or 215 mg/L calcium carbonate.
What dishwasher salt setting should I use in Marana?
For 215 mg/L (12 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Marana?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Town of Marana Water Hardness per System (May 2026) (2026-05). Method: figure published by the water supplier. Town of Marana Water Hardness per System (May 2026) · Outdated figure? Tell us