Water hardness in Darmstadt
19.1 °dH very hard
Tap water in Darmstadt is very hard: 19.1 °dH (341 mg/L · 19.9 gpg · 34.1 °fH).
Source: ENTEGA AG / Hessenwasser - Trinkwasserdaten Versorgungsgebiet Darmstadt (Mittelwerte 2025, Stand 2026) (2025) · data checked 2026-10-19
Range across supply zones: 330–350 mg/L.
ENTEGA and Hessenwasser publish 2025 mean values for the whole Darmstadt supply area. It includes all Darmstadt districts and some neighbouring towns. The figure is 340.9 mg/L CaCO₃ with a narrow range of 330.2 to 349.9 mg/L, so hardness is consistently high. Expect heavy limescale.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 19.1 °dH |
|---|
How Darmstadt compares
- Tap water in Darmstadt is 66 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 96 of 809 in Germany (1 = hardest); 88 % of these cities have softer water.
- In Hessen it is number 8 of 73 cities; the regional median is 10.7 °dH.
- Nearest city with clearly softer water: Pfungstadt, 8 km away (12 °dH).
- Nearest city with clearly harder water: Nußloch, 63 km away (31.6 °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 Darmstadt
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 19 °dH |
| AEG / Electrolux | 5 |
| Beko | 5th |
| Hoover | S3 |
| 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 Darmstadt water hard or soft?
It is very hard: 341 mg/L as CaCO₃ (19.9 gpg, 19.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Darmstadt 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 Darmstadt water?
19.9 gpg, equal to 19.1 °dH, 34.1 °fH or 341 mg/L calcium carbonate.
What dishwasher salt setting should I use in Darmstadt?
For 341 mg/L (19.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Darmstadt?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: ENTEGA AG / Hessenwasser - Trinkwasserdaten Versorgungsgebiet Darmstadt (Mittelwerte 2025, Stand 2026) (2025). Method: figure published by the water supplier. ENTEGA AG / Hessenwasser - Trinkwasserdaten Versorgungsgebiet Darmstadt (Mittelwerte 2025, Stand 2026) · Outdated figure? Tell us