Water hardness in Saarlouis
9.6 °dH hard
Tap water in Saarlouis is hard: 9.6 °dH (171 mg/L · 10 gpg · 17.1 °fH).
Source: Stadtwerke Saarlouis / energis - Trinkwasseruntersuchung Wasserwerk West (Probe 202603697) (2026-05) · data checked 2026-10-23
Range across supply zones: 146–196 mg/L.
2 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Wasserwerk Ost | 8.2 | 146 | hard |
| Wasserwerk West (rechte Kammer) | 11 | 196 | very hard |
Stadtwerke Saarlouis reports two waterworks: Ost at 146.4 mg/L and West at 196.4 mg/L CaCO₃, from a sample dated spring 2026. The city figure of 171.4 mg/L is the median, in the hard class. The West value is from one sampling of the right-hand reservoir chamber, so treat it as a snapshot rather than an annual mean.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 9.6 °dH |
|---|---|
| Utility | Stadtwerke Saarlouis GmbH (SWS, swsls.de) |
How Saarlouis compares
- Tap water in Saarlouis is 17 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 495 of 809 in Germany (1 = hardest); 38 % of these cities have softer water.
- In Saarland it is number 5 of 11 cities; the regional median is 7.9 °dH.
- Nearest city with clearly softer water: Merzig, 17 km away (4.1 °dH).
- Nearest city with clearly harder water: Konz, 43 km away (13.6 °dH).
Ranking of the hardest and softest water in Germany →
What it means at home
- Fast scale on taps, shower screens and kettle; white spots on glassware.
- Water heater: efficiency loss and element failures within years if unprotected.
- Dry skin and dull hair after showering are common.
- Softener recommended; jug or reverse osmosis for drinking.
How much salt will you use for softening?
Recommended, especially with a heater or boiler: scale cuts efficiency and shortens its life.
Descale a coffee machine or kettle about every 2 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Saarlouis
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 10 °dH |
| AEG / Electrolux | 2 |
| Beko | 3rd |
| Hoover | S1 |
| 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 Saarlouis water hard or soft?
It is hard: 171 mg/L as CaCO₃ (10 gpg, 9.6 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Saarlouis 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 Saarlouis water?
10 gpg, equal to 9.6 °dH, 17.1 °fH or 171 mg/L calcium carbonate.
What dishwasher salt setting should I use in Saarlouis?
For 171 mg/L (9.6 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Saarlouis?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Stadtwerke Saarlouis / energis - Trinkwasseruntersuchung Wasserwerk West (Probe 202603697) (2026-05). Method: figure published by the water supplier. Stadtwerke Saarlouis / energis - Trinkwasseruntersuchung Wasserwerk West (Probe 202603697) · Outdated figure? Tell us