Water hardness in Bad Oeynhausen
21.7 °dH very hard
Tap water in Bad Oeynhausen is very hard: 21.7 °dH (387 mg/L · 22.6 gpg · 38.7 °fH).
Source: Stadtwerke Bad Oeynhausen - Wasserqualität, Trinkwasseruntersuchung 30.01.2026 (HBICON Bielefeld) (2026-01) · data checked 2026-10-20
Range across supply zones: 386–389 mg/L.
Stadtwerke Bad Oeynhausen's analysis of 30 January 2026, done by the HBICON laboratory in Bielefeld, gives a computed value of 387.3 mg/L CaCO₃. The range is very narrow, from 385.6 to 389.1 mg/L. This is very hard water, and heavy limescale is to be expected.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 21.7 °dH |
|---|---|
| Utility | Stadtwerke Bad Oeynhausen AöR |
How Bad Oeynhausen compares
- Tap water in Bad Oeynhausen is 89 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 42 of 809 in Germany (1 = hardest); 95 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 7 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Bad Salzuflen, 13 km away (16.3 °dH).
- Nearest city with clearly harder water: Rinteln, 19 km away (28.5 °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 Bad Oeynhausen
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 22 °dH |
| AEG / Electrolux | 5 |
| Beko | 6th |
| Hoover | S3 |
| LG | H4 |
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 Bad Oeynhausen water hard or soft?
It is very hard: 387 mg/L as CaCO₃ (22.6 gpg, 21.7 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Bad Oeynhausen 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 Bad Oeynhausen water?
22.6 gpg, equal to 21.7 °dH, 38.7 °fH or 387 mg/L calcium carbonate.
What dishwasher salt setting should I use in Bad Oeynhausen?
For 387 mg/L (21.7 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Bad Oeynhausen?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadtwerke Bad Oeynhausen - Wasserqualität, Trinkwasseruntersuchung 30.01.2026 (HBICON Bielefeld) (2026-01). Method: computed from supplier's calcium and magnesium. Stadtwerke Bad Oeynhausen - Wasserqualität, Trinkwasseruntersuchung 30.01.2026 (HBICON Bielefeld) · Outdated figure? Tell us