Water hardness in Mendrisio
26 °fH very hard
Tap water in Mendrisio is very hard: 26 °fH (260 mg/L · 15.2 gpg · 14.6 °dH).
Source: AIM Mendrisio, Etichettatura acqua potabile 2026 (zona Mendrisio - Monte Generoso - Capolago) (2026) · data checked 2026-11-14
Range across supply zones: 140–344 mg/L.
8 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °fH | mg/L | ||
|---|---|---|---|
| Arzo - Besazio - Tremona | 25 | 250 | very hard |
| Genestrerio | 24.7 | 247 | very hard |
| Ligornetto alta | 32 | 320 | very hard |
| Ligornetto bassa | 32 | 320 | very hard |
| Mendrisio - Monte Generoso - Capolago | 22 | 220 | very hard |
| Meride | 27 | 270 | very hard |
| Rancate | 29 | 290 | very hard |
| Salorino - Somazzo | 14.5 | 145 | hard |
Aziende Industriali di Mendrisio (AIM) labels its 2026 drinking water by zone. The Mendrisio, Monte Generoso and Capolago zone is listed at 260 mg/L CaCO₃, very hard. Across the eight zones the values run from 140 to 344 mg/L, so the figure for your street may differ. Limescale protection for the boiler and dishwasher is worth considering in the harder zones.
In der Schweiz wird meist in °fH angegeben (1 °fH = 0,56 °dH).
Water data
| Total hardness | 26 °fH |
|---|---|
| Utility | Aziende Industriali di Mendrisio (AIM) |
How Mendrisio compares
- Tap water in Mendrisio is close to the median of the 650 cities we track in Switzerland (26.7 °fH).
- By hardness it ranks 344 of 650 in Switzerland (1 = hardest); 46 % of these cities have softer water.
- In TI it is number 2 of 16 cities; the regional median is 10.9 °fH.
- Nearest city with clearly softer water: Castel San Pietro, 3 km away (17.4 °fH).
- Nearest city with clearly harder water: Diemtigen, 139 km away (37.1 °fH).
Ranking of the hardest and softest water in Switzerland →
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 Mendrisio
| 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 Mendrisio 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 Mendrisio safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. In der Schweiz wird meist in °fH angegeben (1 °fH = 0,56 °dH).
How many grains per gallon is Mendrisio 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 Mendrisio?
For 260 mg/L (14.6 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Mendrisio?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: AIM Mendrisio, Etichettatura acqua potabile 2026 (zona Mendrisio - Monte Generoso - Capolago) (2026). Method: figure published by the water supplier. AIM Mendrisio, Etichettatura acqua potabile 2026 (zona Mendrisio - Monte Generoso - Capolago) · Outdated figure? Tell us