Water hardness in Hanau
15.9 °dH very hard
Tap water in Hanau is very hard: 15.9 °dH (284 mg/L · 16.6 gpg · 28.4 °fH).
Source: Stadtwerke Hanau - Wasserwerk Wilhelmsbad Trinkwasseranalyse (Stand 01/2026) (2026-01) · data checked 2026-10-20
Range across supply zones: 108–450 mg/L.
6 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Wasserwerk Bruchwiesen (Versorgungsgebiet Großauheim) | 7.2 | 128 | hard |
| Wasserwerk Großkrotzenburg (Versorgungsgebiet Wolfgang, Lamboy) | 7.5 | 133 | hard |
| Wasserwerk Leipziger Straße (Versorgungsgebiet Innenstadt) | 13.6 | 242 | very hard |
| Wasserwerk Mittelbuchen (Versorgungsgebiet Mittelbuchen) | 18.3 | 326 | very hard |
| Wasserwerk Wallersee (Versorgungsgebiet Großauheim) | 21.4 | 382 | very hard |
| Wasserwerk Wilhelmsbad (Kesselstadt, Wilhelmsbad, Hohe Tanne) | 24.7 | 441 | very hard |
Stadtwerke Hanau publishes a separate page for each of six waterworks, all dated January 2026, and the values differ sharply. The median is 283.8 mg/L CaCO₃, with a range of 108.0 to 449.8 mg/L. Wilhelmsbad is at the hard end, while Großkrotzenburg and Bruchwiesen are at the soft end. Your district decides which works supplies you, so the city figure is a poor guide at home.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 15.9 °dH |
|---|---|
| Utility | Stadtwerke Hanau |
How Hanau compares
- Tap water in Hanau is 38 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 231 of 809 in Germany (1 = hardest); 71 % of these cities have softer water.
- In Hessen it is number 23 of 73 cities; the regional median is 10.7 °dH.
- Nearest city with clearly softer water: Großkrotzenburg, 5 km away (8.8 °dH).
- Nearest city with clearly harder water: Rüsselsheim am Main, 39 km away (22.4 °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 Hanau
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 16 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| 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 Hanau water hard or soft?
It is very hard: 284 mg/L as CaCO₃ (16.6 gpg, 15.9 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Hanau 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 Hanau water?
16.6 gpg, equal to 15.9 °dH, 28.4 °fH or 284 mg/L calcium carbonate.
What dishwasher salt setting should I use in Hanau?
For 284 mg/L (15.9 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Hanau?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerke Hanau - Wasserwerk Wilhelmsbad Trinkwasseranalyse (Stand 01/2026) (2026-01). Method: computed from supplier's calcium and magnesium. Stadtwerke Hanau - Wasserwerk Wilhelmsbad Trinkwasseranalyse (Stand 01/2026) · Outdated figure? Tell us