Water hardness in Trezzo sull'Adda
22.3 °fH very hard
Tap water in Trezzo sull'Adda is very hard: 22.3 °fH (223 mg/L · 13 gpg · 12.5 °dH).
Source: Gruppo CAP, analisi acquedotto (open data), 2025 Q3–2026 Q2 (2026-06) · data checked 2026-10-19
Range across supply zones: 176–256 mg/L.
Gruppo CAP publishes open data on its network samples, and 56 of them for Trezzo sull'Adda between Q3 2025 and Q2 2026 give a median of 223.0 mg/L CaCO₃, with readings from 176.3 to 255.6 mg/L. Hardness is calculated from calcium and magnesium, and the water counts as very hard. We have not checked which wells serve the town, so check your own address before sizing a softener.
Italian utilities report °f (French degrees); D.Lgs. 31/2001 recommends 15–50 °f.
Water data
| Total hardness | 22.3 °fH |
|---|
How Trezzo sull'Adda compares
- Tap water in Trezzo sull'Adda is 5 % harder than the median of the 629 cities we track in Italy (21.2 °fH).
- By hardness it ranks 292 of 629 in Italy (1 = hardest); 54 % of these cities have softer water.
- In Lombardia it is number 93 of 142 cities; the regional median is 24.9 °fH.
- Nearest city with clearly softer water: Mariano Comense, 28 km away (17 °fH).
- Nearest city with clearly harder water: Cambiago, 7 km away (30.5 °fH).
Ranking of the hardest and softest water in Italy →
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 Trezzo sull'Adda
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| 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 Trezzo sull'Adda water hard or soft?
It is very hard: 223 mg/L as CaCO₃ (13 gpg, 12.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Trezzo sull'Adda safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Italian utilities report °f (French degrees); D.Lgs. 31/2001 recommends 15–50 °f.
How many grains per gallon is Trezzo sull'Adda water?
13 gpg, equal to 12.5 °dH, 22.3 °fH or 223 mg/L calcium carbonate.
What dishwasher salt setting should I use in Trezzo sull'Adda?
For 223 mg/L (12.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Trezzo sull'Adda?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Gruppo CAP, analisi acquedotto (open data), 2025 Q3–2026 Q2 (2026-06). Method: computed from supplier's calcium and magnesium. Gruppo CAP, analisi acquedotto (open data), 2025 Q3–2026 Q2 · Outdated figure? Tell us