Water hardness in Vannes
9.7 °fH moderately hard
Tap water in Vannes is moderately hard: 9.7 °fH (97 mg/L · 5.7 gpg · 5.4 °dH).
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 56260 (2026-08) · data checked 2026-10-19
Range across supply zones: 81–97 mg/L.
Around Vannes, drinking water is mostly taken from rivers of the Morbihan, on old bedrock. It is lightly mineralised: 97.0 mg/L CaCO₃, between 81.0 and 97.0 mg/L. This is fairly soft water, and scale stays low.
TH en °fH : douce < 15, moyennement dure 15–25, dure 25–35, très dure > 35 °fH (classes usuelles ARS).
Water data
| Total hardness | 9.7 °fH |
|---|---|
| Utility | Ca Golfe Du Morbihan - Vannes Agglomération |
How Vannes compares
- Tap water in Vannes is 59 % softer than the median of the 33641 cities we track in France (23.9 °fH).
- By hardness it ranks 29111 of 33641 in France (1 = hardest); 13 % of these cities have softer water.
- In Morbihan it is number 225 of 230 cities; the regional median is 12.9 °fH.
- Nearest city with clearly softer water: Baye, 67 km away (7.6 °fH).
- Nearest city with clearly harder water: Saint-Avé, 4 km away (14.2 °fH).
Ranking of the hardest and softest water in France →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Vannes
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Vannes water hard or soft?
It is moderately hard: 97 mg/L as CaCO₃ (5.7 gpg, 5.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Vannes 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 Vannes water?
5.7 gpg, equal to 5.4 °dH, 9.7 °fH or 97 mg/L calcium carbonate.
What dishwasher salt setting should I use in Vannes?
For 97 mg/L (5.4 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Vannes?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 56260 (2026-08). Method: own measurement. Ministère de la Santé (ARS), contrôle sanitaire SISE-Eaux, commune 56260 · Outdated figure? Tell us