Water hardness in Königswinter
6.8 °dH hard
Tap water in Königswinter is hard: 6.8 °dH (121 mg/L · 7.1 gpg · 12.1 °fH).
Source: rhenag Mitteilung über die Trinkwasserbeschaffenheit (Wasserhärte 2022-2023) (2023) · data checked 2026-10-23
This figure is a zone value, not a town-wide one. rhenag's notice covers only Altstadt, Nieder- and Oberdollendorf and Römlinghoven, with 121.4 mg/L CaCO₃ (6.8 °dH ± 0.8), labelled soft. The notice dates from 2022-2023 and is the newest we found, so the number may be out of date. Other districts of Königswinter are not covered by this line and may differ.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 6.8 °dH |
|---|---|
| Utility | rhenag Rheinische Energie- und Wasserversorgung AG |
How Königswinter compares
- Tap water in Königswinter is 41 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 642 of 809 in Germany (1 = hardest); 19 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 127 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Siegburg, 15 km away (4.8 °dH).
- Nearest city with clearly harder water: Bad Honnef, 4 km away (14.4 °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 Königswinter
| Brand | Setting for this water |
|---|---|
| Bosch | H01 |
| Miele | 7 °dH |
| AEG / Electrolux | 2 |
| Beko | 2nd |
| 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 Königswinter water hard or soft?
It is hard: 121 mg/L as CaCO₃ (7.1 gpg, 6.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Königswinter 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 Königswinter water?
7.1 gpg, equal to 6.8 °dH, 12.1 °fH or 121 mg/L calcium carbonate.
What dishwasher salt setting should I use in Königswinter?
For 121 mg/L (6.8 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Königswinter?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: rhenag Mitteilung über die Trinkwasserbeschaffenheit (Wasserhärte 2022-2023) (2023). Method: figure published by the water supplier. rhenag Mitteilung über die Trinkwasserbeschaffenheit (Wasserhärte 2022-2023) · Outdated figure? Tell us