Water hardness in Guidonia Montecelio
33.3 °fH very hard
Tap water in Guidonia Montecelio is very hard: 33.3 °fH (333 mg/L · 19.5 gpg · 18.7 °dH).
Source: Acea Ato 2, qualità dell'acqua per zona (valori mediani) (2026-07) · data checked 2026-10-20
Range across supply zones: 315–351 mg/L.
Guidonia Montecelio sits north-east of Rome in the Acea Ato 2 area, where the supply is mostly Apennine spring water via aqueducts plus local sources, among them springs such as the Acquoria near Tivoli; we have not confirmed which intake feeds Guidonia Montecelio. Published analyses give a typical value of 333.4 mg/L CaCO₃, with readings from 315.4 to 351.4 mg/L, which counts as very hard water. Expect scale on kettles, shower heads and in the water heater, and descaling about as often as a hard-water kitchen requires.
Italian utilities report °f (French degrees); D.Lgs. 31/2001 recommends 15–50 °f.
Water data
| Total hardness | 33.3 °fH |
|---|
How Guidonia Montecelio compares
- Tap water in Guidonia Montecelio is 57 % harder than the median of the 629 cities we track in Italy (21.2 °fH).
- By hardness it ranks 58 of 629 in Italy (1 = hardest); 91 % of these cities have softer water.
- In Lazio it is number 14 of 54 cities; the regional median is 27.2 °fH.
- Nearest city with clearly softer water: Monterotondo, 11 km away (26 °fH).
- Nearest city with clearly harder water: Fiano Romano, 21 km away (62 °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 Guidonia Montecelio
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 19 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| 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 Guidonia Montecelio water hard or soft?
It is very hard: 333 mg/L as CaCO₃ (19.5 gpg, 18.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Guidonia Montecelio 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 Guidonia Montecelio water?
19.5 gpg, equal to 18.7 °dH, 33.3 °fH or 333 mg/L calcium carbonate.
What dishwasher salt setting should I use in Guidonia Montecelio?
For 333 mg/L (18.7 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Guidonia Montecelio?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Acea Ato 2, qualità dell'acqua per zona (valori mediani) (2026-07). Method: computed from supplier's calcium and magnesium. Acea Ato 2, qualità dell'acqua per zona (valori mediani) · Outdated figure? Tell us