Water hardness in Passau
10.2 °dH very hard
Tap water in Passau is very hard: 10.2 °dH (182 mg/L · 10.6 gpg · 18.2 °fH).
Source: Stadtwerke Passau, Trinkwasser-Analysewerte Wassergewinnungsgebiet Insel Soldatenau (2025-08) · data checked 2026-10-20
Stadtwerke Passau's August 2025 analysis for the Insel Soldatenau extraction area reports 182.1 mg/L CaCO₃, which is very hard. The figure describes that source rather than every address in the city. Confirm with the utility if you live outside the main supply area.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 10.2 °dH |
|---|---|
| Utility | Stadtwerke Passau GmbH |
How Passau compares
- Tap water in Passau is 11 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 474 of 809 in Germany (1 = hardest); 41 % of these cities have softer water.
- In Bayern it is number 109 of 137 cities; the regional median is 15.8 °dH.
- Nearest city with clearly softer water: Wegscheid, 26 km away (4.6 °dH).
- Nearest city with clearly harder water: Ruhstorf an der Rott, 30 km away (17.5 °dH).
Ranking of the hardest and softest water in Germany →
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 Passau
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| 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 Passau water hard or soft?
It is very hard: 182 mg/L as CaCO₃ (10.6 gpg, 10.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Passau safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
How many grains per gallon is Passau water?
10.6 gpg, equal to 10.2 °dH, 18.2 °fH or 182 mg/L calcium carbonate.
What dishwasher salt setting should I use in Passau?
For 182 mg/L (10.2 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Passau?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerke Passau, Trinkwasser-Analysewerte Wassergewinnungsgebiet Insel Soldatenau (2025-08). Method: figure published by the water supplier. Stadtwerke Passau, Trinkwasser-Analysewerte Wassergewinnungsgebiet Insel Soldatenau · Outdated figure? Tell us