Water hardness in Lahnstein
14.5 °dH very hard
Tap water in Lahnstein is very hard: 14.5 °dH (259 mg/L · 15.1 gpg · 25.9 °fH).
Source: Vereinigte Wasserwerke Mittelrhein GmbH, Bekanntmachung der Wasserhärte Lahnstein (Koblenz, November 2023) (2023-11) · data checked 2026-11-03
Range across supply zones: 232–286 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Niederlahnstein oberhalb der Bahnlinie Koblenz-Gießen, einschließlich Allerheiligenberg und Lichterkopf, ohne Straße Zur Ruppertsklamm | 13 | 232 | very hard |
| Oberlahnstein, Friedrichssegen, Lahnstein auf der Höhe, Niederlahnstein unterhalb der Bahnlinie Koblenz-Gießen und Straße Zur Ruppertsklamm | 16 | 286 | very hard |
Vereinigte Wasserwerke Mittelrhein published two zones for Lahnstein in November 2023. Oberlahnstein, Friedrichssegen, Lahnstein auf der Höhe and Niederlahnstein below the Koblenz-Gießen railway read 16.0 °dH (hard). Niederlahnstein above the railway, including Allerheiligenberg and Lichterkopf, reads 13.0 °dH (medium). The notice is almost three years old, so the figures may have moved; your street decides which of the two applies.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 14.5 °dH |
|---|---|
| Utility | Vereinigte Wasserwerke Mittelrhein GmbH (VWM) |
How Lahnstein compares
- Tap water in Lahnstein is 26 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 272 of 809 in Germany (1 = hardest); 66 % of these cities have softer water.
- In Rheinland-Pfalz it is number 7 of 25 cities; the regional median is 9.9 °dH.
- Nearest city with clearly softer water: Ransbach-Baumbach, 17 km away (4.3 °dH).
- Nearest city with clearly harder water: Limburg an der Lahn, 32 km away (23.3 °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 Lahnstein
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 14 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| 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 Lahnstein water hard or soft?
It is very hard: 259 mg/L as CaCO₃ (15.1 gpg, 14.5 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Lahnstein 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 Lahnstein water?
15.1 gpg, equal to 14.5 °dH, 25.9 °fH or 259 mg/L calcium carbonate.
What dishwasher salt setting should I use in Lahnstein?
For 259 mg/L (14.5 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Lahnstein?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Vereinigte Wasserwerke Mittelrhein GmbH, Bekanntmachung der Wasserhärte Lahnstein (Koblenz, November 2023) (2023-11). Method: figure published by the water supplier. Vereinigte Wasserwerke Mittelrhein GmbH, Bekanntmachung der Wasserhärte Lahnstein (Koblenz, November 2023) · Outdated figure? Tell us