Water hardness in Dorsten
13.5 °dH very hard
Tap water in Dorsten is very hard: 13.5 °dH (241 mg/L · 14.1 gpg · 24.1 °fH).
Source: RWW, Trinkwasserdaten 2025 (2025) · data checked 2026-10-20
Range across supply zones: 225–252 mg/L.
RWW's 2025 data gives Dorsten a median of 240.9 mg/L CaCO₃, with a narrow range of 224.9 to 251.7 mg/L. The water is in the very hard category throughout. Because the spread is small, one figure is a fair guide for most addresses in the supply area.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 13.5 °dH |
|---|
How Dorsten compares
- Tap water in Dorsten is 17 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 319 of 809 in Germany (1 = hardest); 60 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 47 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Bottrop, 16 km away (10.8 °dH).
- Nearest city with clearly harder water: Rhede, 27 km away (19.1 °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 Dorsten
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 13 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| 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 Dorsten water hard or soft?
It is very hard: 241 mg/L as CaCO₃ (14.1 gpg, 13.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Dorsten 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 Dorsten water?
14.1 gpg, equal to 13.5 °dH, 24.1 °fH or 241 mg/L calcium carbonate.
What dishwasher salt setting should I use in Dorsten?
For 241 mg/L (13.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Dorsten?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: RWW, Trinkwasserdaten 2025 (2025). Method: figure published by the water supplier. RWW, Trinkwasserdaten 2025 · Outdated figure? Tell us