Is 9th harder than 10th.

Water hardness - quality of Viennese drinking water

The water hardness (total hardness) depends on the minerals that the water absorbs from the soil. The water supply companies in Austria differentiate between three levels of hardness:

  • I: 0 to 10 ° dH (degree of German hardness) - soft
  • II: 10 to 16 ° dH (degree of German hardness) - medium
  • III: over 16 ° dH (degree of German hardness) - hard

The dosage of detergent and anti-limescale agent (softener) is based on these hardness levels. The dishwasher must be set according to the respective hardness level (see operating instructions).

For setting the water hardness in household appliances, Wiener Wasser generally recommends selecting the setting <10 ° dH (degree of German hardness). No increased detergent or anti-limescale detergent is required for this.

Viennese drinking water has a hardness of 6 to 11 (in some cases 16) ° dH (degree of German hardness). A tape service from Wiener Wasser provides information about the water hardness range in the individual districts of Vienna:
Phone: +43 1 599 59-32900

Water hardness in the 23 districts of Vienna

district

Water hardness ° dH
(Degree of German hardness)

Water hardness mmol / l
(Millimoles per liter)

1

6°-11°

1,07-1,96

2

6°-11°/ 6°-16°*)

1,07-1,96/ 1,07-2,85*)

3

6°-11°/ 6°-16°*)

1,07-1,96 / 1,07-2,85*)

4

6°-11°

1,07-1,96

5

6°-11°

1,07-1,96

6

6°-11°

1,07-1,96

7

6°-11°

1,07-1,96

8

6°-11°

1,07-1,96

9

6°-11°

1,07-1,96

10

6°-11°

1,07-1,96

11

6°-11°/ 6°-16°*)

1,07-1,96/ 1,07-2,85*)

12

6°-11°

1,07-1,96

13

6°-11°

1,07-1,96

14

6°-11°

1,07-1,96

15

6°-11°

1,07-1,96

16

6°-11°

1,07-1,96

17

6°-11°

1,07-1,96

18

6°-11°

1,07-1,96

19

6°-11°

1,07-1,96

20

6°-11°/ 6°-16°*)

1,07-1,96/ 1,07-2,85*)

21

6°-11°/ 6°-16°*)

1,07-1,96/ 1,07-2,85*)

22

6°-11°/ 6°-16°*)

1,07-1,96/ 1,07-2,85*)

23

6°-11°

1,07-1,96

Notes and explanations

*) In exceptional cases, the feed of groundwater can cause the water hardness to rise to 16 ° dH. This applies to districts 2, 3, 11, 20, 21 and 22. Some device manufacturers do not use ° dH in the operating instructions, but rather millimoles per liter (mmol / l) or other hardness specifications.

1.5 millimoles of calcium carbonate per liter correspond to 8.4 ° dH (degree of German hardness)

Additional information

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City of Vienna | Viennese water
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