Water hardness in Mexico
15.2 gpg very hard
Tap water in Mexico is very hard: 15.2 gpg (260 mg/L · 14.6 °dH · 26 °fH).
Source: Missouri American Water, water quality report (Mexico) (2025) · data checked 2026-10-20
Range across supply zones: 140–260 mg/L.
Mexico, Missouri, is supplied by Missouri American Water. Its 2025 water quality report gives 260 mg/L as CaCO₃, with values from 140 to 260 mg/L, so the figure shown is the top of the range. That is very hard water. Check the latest report if you need a precise value for sizing a softener.
USGS classes: soft 0–60, moderately hard 61–120, hard 121–180, very hard >180 mg/L.
Water data
| Total hardness | 15.2 gpg |
|---|---|
| Utility | Missouri American Water |
How Mexico compares
- Tap water in Mexico is 68 % harder than the median of the 1372 cities we track in the United States (9.1 gpg).
- By hardness it ranks 353 of 1372 in the United States (1 = hardest); 74 % of these cities have softer water.
- In Missouri it is number 5 of 32 cities; the regional median is 10.3 gpg.
- Nearest city with clearly softer water: Jefferson City, 70 km away (8.8 gpg).
- Nearest city with clearly harder water: Wardsville, 79 km away (19.7 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 Mexico
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 15 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
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 Mexico water hard or soft?
It is very hard: 260 mg/L as CaCO₃ (15.2 gpg, 14.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Mexico 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 Mexico water?
15.2 gpg, equal to 14.6 °dH, 26 °fH or 260 mg/L calcium carbonate.
What dishwasher salt setting should I use in Mexico?
For 260 mg/L (14.6 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Mexico?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Missouri American Water, water quality report (Mexico) (2025). Method: figure published by the water supplier. Missouri American Water, water quality report (Mexico) · Outdated figure? Tell us