Water hardness in Mainhardt
17.3 °dH very hard
Tap water in Mainhardt is very hard: 17.3 °dH (309 mg/L · 18 gpg · 30.9 °fH).
Source: Gemeinde Mainhardt: Trinkwasseruntersuchung, routinemaessige Untersuchungen (2024) (2024) · data checked 2026-11-06
Range across supply zones: 298–320 mg/L.
The municipality of Mainhardt published results of routine drinking-water tests for its local network in 2024. They range from 298.1 to 319.5 mg/L CaCO₃, and the 308.8 mg/L figure (very hard) is computed from them rather than measured as a single value. Individual samples can therefore come out a little higher or lower.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 17.3 °dH |
|---|---|
| Utility | Gemeinde Mainhardt (Ortsnetz) |
How Mainhardt compares
- Tap water in Mainhardt is 50 % harder than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 174 of 809 in Germany (1 = hardest); 78 % of these cities have softer water.
- In Baden-Württemberg it is number 33 of 146 cities; the regional median is 12.8 °dH.
- Nearest city with clearly softer water: Neuenstein, 14 km away (13.8 °dH).
- Nearest city with clearly harder water: Beilstein, 18 km away (23 °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 Mainhardt
| Brand | Setting for this water |
|---|---|
| Bosch | H05 |
| Miele | 17 °dH |
| AEG / Electrolux | 4 |
| Beko | 5th |
| Hoover | S3 |
| 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 Mainhardt water hard or soft?
It is very hard: 309 mg/L as CaCO₃ (18 gpg, 17.3 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Mainhardt 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 Mainhardt water?
18 gpg, equal to 17.3 °dH, 30.9 °fH or 309 mg/L calcium carbonate.
What dishwasher salt setting should I use in Mainhardt?
For 309 mg/L (17.3 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Mainhardt?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Gemeinde Mainhardt: Trinkwasseruntersuchung, routinemaessige Untersuchungen (2024) (2024). Method: computed from supplier's calcium and magnesium. Gemeinde Mainhardt: Trinkwasseruntersuchung, routinemaessige Untersuchungen (2024) · Outdated figure? Tell us