Water hardness in Siegburg
4.8 °dH moderately hard
Tap water in Siegburg is moderately hard: 4.8 °dH (86 mg/L · 5 gpg · 8.6 °fH).
Source: rhenag Mitteilung über die Trinkwasserbeschaffenheit (Bekanntgabe der Härte) (2023-12) · data checked 2026-10-23
The figure of 85.7 mg/L CaCO₃ comes from a rhenag notice on drinking water quality dated December 2023, so it is older than most entries here. It places Siegburg in the moderate class. Check the utility's current notice if you want to confirm it before buying a softener.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 4.8 °dH |
|---|---|
| Utility | rhenag Rheinische Energie AG (Wasser) |
How Siegburg compares
- Tap water in Siegburg is 58 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 738 of 809 in Germany (1 = hardest); 9 % of these cities have softer water.
- In Nordrhein-Westfalen it is number 142 of 153 cities; the regional median is 11.3 °dH.
- Nearest city with clearly softer water: Sprockhövel, 49 km away (3.5 °dH).
- Nearest city with clearly harder water: Bornheim (Rhein-Sieg), 8 km away (12 °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 Siegburg
| 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 Siegburg water hard or soft?
It is moderately hard: 86 mg/L as CaCO₃ (5 gpg, 4.8 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Siegburg 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 Siegburg water?
5 gpg, equal to 4.8 °dH, 8.6 °fH or 86 mg/L calcium carbonate.
What dishwasher salt setting should I use in Siegburg?
For 86 mg/L (4.8 °dH) check your manufacturer's table: level 2–3.
Do I need a water softener in Siegburg?
Not essential; a scale inhibitor protects the heater cheaply.
Source
Source: rhenag Mitteilung über die Trinkwasserbeschaffenheit (Bekanntgabe der Härte) (2023-12). Method: figure published by the water supplier. rhenag Mitteilung über die Trinkwasserbeschaffenheit (Bekanntgabe der Härte) · Outdated figure? Tell us