Water hardness in Filderstadt
9.1 °dH hard
Tap water in Filderstadt is hard: 9.1 °dH (162 mg/L · 9.5 gpg · 16.2 °fH).
Source: Stadtwerke Filderstadt, Wasserinfo Wasserhärte 2026 (Stand 03.06.2026) (2026-06) · data checked 2026-10-23
Range across supply zones: 162–180 mg/L.
6 supply zones — hardness varies by neighbourhood; the figure above is the median.
Hardness by district / supply zone
| °dH | mg/L | ||
|---|---|---|---|
| Bernhausen (Bodenseewasser) | 9.1 | 162 | hard |
| Bonlanden (Bodenseewasser) | 9.1 | 162 | hard |
| Harthausen (Bodenseewasser) | 9.1 | 162 | hard |
| Harthausen (Filderwasser) | 10.1 | 180 | very hard |
| Plattenhardt (Bodenseewasser) | 9.1 | 162 | hard |
| Sielmingen (Filderwasser) | 10.1 | 180 | very hard |
Stadtwerke Filderstadt publishes a hardness sheet updated in June 2026 for six supply areas. Bernhausen, Bonlanden, Harthausen and Plattenhardt are listed with Lake Constance water at 162.4 mg/L CaCO₃, while Sielmingen and part of Harthausen receive Filderwasser at 180.3 mg/L. The gap is small, and the town figure is 162.4 mg/L. Filderstadt is clearly softer than nearby Sindelfingen at 294.5 mg/L.
German law (WRMG) uses 3 bands: soft < 8.4 °dH, medium 8.4–14 °dH, hard > 14 °dH.
Water data
| Total hardness | 9.1 °dH |
|---|---|
| Utility | Stadtwerke Filderstadt |
How Filderstadt compares
- Tap water in Filderstadt is 21 % softer than the median of the 809 cities we track in Germany (11.5 °dH).
- By hardness it ranks 521 of 809 in Germany (1 = hardest); 35 % of these cities have softer water.
- In Baden-Württemberg it is number 112 of 146 cities; the regional median is 12.8 °dH.
- Nearest city with clearly softer water: Neubulach, 37 km away (3.5 °dH).
- Nearest city with clearly harder water: Wendlingen am Neckar, 14 km away (17 °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 Filderstadt
| Brand | Setting for this water |
|---|---|
| Bosch | H02 |
| Miele | 9 °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 Filderstadt water hard or soft?
It is hard: 162 mg/L as CaCO₃ (9.5 gpg, 9.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Filderstadt 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 Filderstadt water?
9.5 gpg, equal to 9.1 °dH, 16.2 °fH or 162 mg/L calcium carbonate.
What dishwasher salt setting should I use in Filderstadt?
For 162 mg/L (9.1 °dH) check your manufacturer's table: level 4–5.
Do I need a water softener in Filderstadt?
Recommended if you have a water heater, boiler or tankless unit: it saves repairs and detergent.
Source
Source: Stadtwerke Filderstadt, Wasserinfo Wasserhärte 2026 (Stand 03.06.2026) (2026-06). Method: figure published by the water supplier. Stadtwerke Filderstadt, Wasserinfo Wasserhärte 2026 (Stand 03.06.2026) · Outdated figure? Tell us