Water hardness in Käerjeng
18.1 °fH very hard
Tap water in Käerjeng is very hard: 18.1 °fH (181 mg/L · 10.6 gpg · 10.1 °dH).
Source: Administration de la gestion de l'eau (AGE), Dureté de l'eau (data.public.lu, CC0) (2022) · data checked 2026-10-20
This figure is over 3 years old; hardness may have changed.
Luxembourg's public supply relies largely on springs and wells in the Luxembourg sandstone, with some surface water from the Upper Sûre reservoir supplied via the SEBES syndicate. The reported hardness is 181.1 mg/L CaCO₃. This figure dates from 2022 and may have changed. Scale forms fast on heaters and fittings; a water softener is a common remedy.
Luxembourg communes report hardness in °fH (and °dH).
Water data
| Total hardness | 18.1 °fH |
|---|---|
| Utility | Commune de Käerjeng |
How Käerjeng compares
- Tap water in Käerjeng is close to the median of the 101 cities we track in Luxembourg (18.2 °fH).
- By hardness it ranks 53 of 101 in Luxembourg (1 = hardest); 48 % of these cities have softer water.
- In Capellen it is number 7 of 9 cities; the regional median is 23.6 °fH.
- Nearest city with clearly softer water: Strassen, 13 km away (13.8 °fH).
- Nearest city with clearly harder water: Mamer, 11 km away (23.6 °fH).
Ranking of the hardest and softest water in Luxembourg →
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 Käerjeng
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| 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 Käerjeng water hard or soft?
It is very hard: 181 mg/L as CaCO₃ (10.6 gpg, 10.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Käerjeng safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Luxembourg communes report hardness in °fH (and °dH).
How many grains per gallon is Käerjeng water?
10.6 gpg, equal to 10.1 °dH, 18.1 °fH or 181 mg/L calcium carbonate.
What dishwasher salt setting should I use in Käerjeng?
For 181 mg/L (10.1 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Käerjeng?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Administration de la gestion de l'eau (AGE), Dureté de l'eau (data.public.lu, CC0) (2022). Method: figure published by the water supplier. Administration de la gestion de l'eau (AGE), Dureté de l'eau (data.public.lu, CC0) · Outdated figure? Tell us