Water hardness in Illertissen
14.2 °dH very hard
Tap water in Illertissen is very hard: 14.2 °dH (254 mg/L · 14.8 gpg · 25.4 °fH).
Source: Stadt Illertissen, Wasseranalyse (Analysebericht 2505040), Probe 15.05.2025 (2025-05) · data checked 2026-11-03
The town of Illertissen publishes a lab report for a single distribution sample taken on 15 May 2025. It shows 253.4 mg/L CaCO₃, just above the hard threshold in the WRMG. One sample cannot show seasonal change or differences between streets, so treat the figure as indicative. The report does not name the water source, and an older 2024 report is a scan we could not read.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 14.2 °dH |
|---|
How Illertissen compares
- Tap water in Illertissen is 23 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 292 of 809 in Germany (1 = hardest); 64 % of these cities have softer water.
- In Bayern it is number 82 of 137 cities; the regional median is 15.8 °dH.
- Nearest city with clearly softer water: Meitingen, 62 km away (9 °dH).
- Nearest city with clearly harder water: Schwendi, 20 km away (19 °dH).
Ranking of the hardest and softest water in Germany →
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 Illertissen
| Brand | Setting for this water |
|---|---|
| Bosch | H04 |
| Miele | 14 °dH |
| AEG / Electrolux | 3 |
| Beko | 4th |
| Hoover | S2 |
| LG | H3 |
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 Illertissen water hard or soft?
It is very hard: 254 mg/L as CaCO₃ (14.8 gpg, 14.2 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Illertissen 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 Illertissen water?
14.8 gpg, equal to 14.2 °dH, 25.4 °fH or 254 mg/L calcium carbonate.
What dishwasher salt setting should I use in Illertissen?
For 254 mg/L (14.2 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Illertissen?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Stadt Illertissen, Wasseranalyse (Analysebericht 2505040), Probe 15.05.2025 (2025-05). Method: figure published by the water supplier. Stadt Illertissen, Wasseranalyse (Analysebericht 2505040), Probe 15.05.2025 · Outdated figure? Tell us