Water Hardness Atlas ZIP / postcode

Water hardness in Montlouis-sur-Loire

17.4 °fH hard

Tap water in Montlouis-sur-Loire is hard: 17.4 °fH (174 mg/L · 10.2 gpg · 9.7 °dH).

<6060–120120–180>180 mg/L

Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 37156 (2026-08) · data checked 2026-10-19

In Montlouis-sur-Loire (Indre-et-Loire), the ARS health-control record (SISE-Eaux, commune 37156) gives a hardness of 174 mg/L CaCO₃, which is hard water. The measurement dates from August 2026 and the listed service is the municipality.

TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).

Water data

Total hardness17.4 °fH
UtilityMairie De Montlouis Sur Loire

How Montlouis-sur-Loire compares

Ranking of the hardest and softest water in France →

What it means at home

How much salt will you use for softening?

Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.

Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).

Estimates for planning, not a quote. Check your appliance manual for exact settings.

Dishwasher setting in Montlouis-sur-Loire

BrandSetting for this water
BoschH02
Miele10 °dH
AEG / Electrolux2
Beko3rd
HooverS1
LGH2

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 Montlouis-sur-Loire water hard or soft?

It is hard: 174 mg/L as CaCO₃ (10.2 gpg, 9.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.

Is tap water in Montlouis-sur-Loire safe to drink?

Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).

How many grains per gallon is Montlouis-sur-Loire water?

10.2 gpg, equal to 9.7 °dH, 17.4 °fH or 174 mg/L calcium carbonate.

What dishwasher salt setting should I use in Montlouis-sur-Loire?

For 174 mg/L (9.7 °dH) check your manufacturer's table: level 4–5.

Do I need a water softener in Montlouis-sur-Loire?

Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.

Source

Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 37156 (2026-08). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 37156 · Outdated figure? Tell us

Nearby cities

Vouvray25.6 °fHLarçay20.4 °fHVéretz21.1 °fHVernou-sur-Brenne25.6 °fHAzay-sur-Cher21.1 °fHLa Ville-aux-Dames29.1 °fH
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