Water hardness in Gronau (Westf.)
16 °dH very hard
Tap water in Gronau (Westf.) is very hard: 16 °dH (286 mg/L · 16.7 gpg · 28.6 °fH).
Source: Stadtwerke Gronau Trinkwasseranalyse 2025 (PDF) (2025-10) · data checked 2026-10-20
Range across supply zones: 250–321 mg/L.
Stadtwerke Gronau's 2025 analysis gives a computed value of 285.6 mg/L CaCO₃ for Gronau (Westf.), in a range of 249.9 to 321.3 mg/L. The water is very hard. As the value is computed from the published figures, treat it as a good estimate rather than a single measurement.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 16 °dH |
|---|---|
| Utility | Stadtwerke Gronau GmbH |
How Gronau (Westf.) compares
- Tap water in Gronau (Westf.) is 39 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 223 of 809 in Germany (1 = hardest); 72 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 22 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Ahaus, 15 km away (11 °dH).
- Nearest city with clearly harder water: Bünde, 106 km away (21.7 °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 Gronau (Westf.)
| 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 Gronau (Westf.) water hard or soft?
It is very hard: 286 mg/L as CaCO₃ (16.7 gpg, 16 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Gronau (Westf.) 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 Gronau (Westf.) water?
16.7 gpg, equal to 16 °dH, 28.6 °fH or 286 mg/L calcium carbonate.
What dishwasher salt setting should I use in Gronau (Westf.)?
For 286 mg/L (16 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Gronau (Westf.)?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerke Gronau Trinkwasseranalyse 2025 (PDF) (2025-10). Method: computed from supplier's calcium and magnesium. Stadtwerke Gronau Trinkwasseranalyse 2025 (PDF) · Outdated figure? Tell us