Water hardness in Kaiserslautern
5.4 °dH moderately hard
Tap water in Kaiserslautern is moderately hard: 5.4 °dH (96 mg/L · 5.6 gpg · 9.6 °fH).
Source: Stadtwerke Kaiserslautern (SWK) Trinkwasseranalyse, Wasserwerk Barbarossastraße (2026-01) · data checked 2026-10-20
Range across supply zones: 73–98 mg/L.
3 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Wasserwerk Barbarossastraße (single tap sample, Kaiserslautern Fachhochschule) | 5.5 | 98 | moderately hard |
| Wasserwerk Mölschbach (single tap sample, Kaiserslautern-Mölschbach) | 4.1 | 73 | moderately hard |
| Wasserwerk Rote Hohl (single tap sample, Kaiserslautern-Dansenberg) | 5.4 | 96 | moderately hard |
Stadtwerke Kaiserslautern published three separate analyses of single tap samples, all taken on 20 January 2026, one each at the Barbarossa, Rote Hohl and Mölschbach works. They give a median of 96.4 mg/L CaCO₃ and a range of 73.2 to 98.2 mg/L. A single sample is not an annual mean, so the true spread may be wider. Water at this level is soft to moderate and produces little scale.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 5.4 °dH |
|---|---|
| Utility | Stadtwerke Kaiserslautern (SWK) |
How Kaiserslautern compares
- Tap water in Kaiserslautern is 53 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 721 of 809 in Germany (1 = hardest); 11 % of these cities have softer water.
- In Rheinland-Pfalz it is number 18 of 25 cities; the regional median is 9.9 °dH.
- Nearest city with clearly softer water: Annweiler am Trifels, 29 km away (2.9 °dH).
- Nearest city with clearly harder water: Schönenberg-Kübelberg, 27 km away (8.3 °dH).
Ranking of the hardest and softest water in Germany →
What it means at home
- Visible kettle scale every few weeks; vinegar or citric acid is enough.
- Water heater and washing machine: some long-term scale; a scale inhibitor slows it.
- Dishwasher: medium salt setting.
- Softener optional; pays off mainly with a gas boiler or tankless heater.
How much salt will you use for softening?
Optional. A scale inhibitor or a small softener protects the heater; soap savings are modest.
Descale a coffee machine or kettle about every 3 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Kaiserslautern
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 5 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| Hoover | S1 |
| LG | H1 |
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 Kaiserslautern water hard or soft?
It is moderately hard: 96 mg/L as CaCO₃ (5.6 gpg, 5.4 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Kaiserslautern 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 Kaiserslautern water?
5.6 gpg, equal to 5.4 °dH, 9.6 °fH or 96 mg/L calcium carbonate.
What dishwasher salt setting should I use in Kaiserslautern?
For 96 mg/L (5.4 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Kaiserslautern?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: Stadtwerke Kaiserslautern (SWK) Trinkwasseranalyse, Wasserwerk Barbarossastraße (2026-01). Method: figure published by the water supplier. Stadtwerke Kaiserslautern (SWK) Trinkwasseranalyse, Wasserwerk Barbarossastraße · Outdated figure? Tell us