Water hardness in Zagreb
364 mg/L very hard
Tap water in Zagreb is very hard: 364 mg/L (21.3 gpg · 20.4 °dH · 36.4 °fH).
Source: VIO zone report ZO Zagreb-Zapad, lab results Feb 2025 (Ukupna tvrdoća mg CaCO3/l, min/max over 9 samples) (2025-02) · data checked 2026-10-22
Range across supply zones: 332–396 mg/L.
VIO, the Zagreb utility, publishes monthly lab reports per supply zone. The figure here is the Zagreb-Zapad zone only: 332 to 396 mg/L CaCO3 across 9 samples in February 2025, with no average printed. Other Zagreb zones could not be checked because the utility's quality table was unavailable, so your address may differ. Croatian rules list hardness as a monitored parameter but set no limit.
Croatian suppliers report total hardness in mg/L CaCO₃ or °dH.
Water data
| Total hardness | 364 mg/L |
|---|---|
| Utility | Vodoopskrba i odvodnja d.o.o. (VIO) |
How Zagreb compares
- Tap water in Zagreb is 7 % harder than the median of the 13 cities we track in Croatia (339 mg/L).
- By hardness it ranks 4 of 13 in Croatia (1 = hardest); 75 % of these cities have softer water.
- Nearest city with clearly softer water: Čakovec, 72 km away (218 mg/L).
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 Zagreb
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 20 °dH |
| AEG / Electrolux | 5 |
| Beko | 6th |
| 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 Zagreb water hard or soft?
It is very hard: 364 mg/L as CaCO₃ (21.3 gpg, 20.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Zagreb safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Croatian suppliers report total hardness in mg/L CaCO₃ or °dH.
How many grains per gallon is Zagreb water?
21.3 gpg, equal to 20.4 °dH, 36.4 °fH or 364 mg/L calcium carbonate.
What dishwasher salt setting should I use in Zagreb?
For 364 mg/L (20.4 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Zagreb?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: VIO zone report ZO Zagreb-Zapad, lab results Feb 2025 (Ukupna tvrdoća mg CaCO3/l, min/max over 9 samples) (2025-02). Method: computed from supplier's calcium and magnesium. VIO zone report ZO Zagreb-Zapad, lab results Feb 2025 (Ukupna tvrdoća mg CaCO3/l, min/max over 9 samples) · Outdated figure? Tell us