In the manual of my new dishwasher there is a table of values of water hardness. It goes until 50 dGH (degrees of general hardness) which corresponds to 9,0 mmol/l in the same table.

From wikipedia:

1 dGH is equivalent to 0.17832 mmol per litre of elemental calcium and/or magnesium ions

The interesting thing is that 6 out of the 10 options for water softener levels are for water hardness greater than 19 dGH and most websites consider 20 dGH as very hard water already.

I couldn't' find any world map or regional map from any place containing dGH values greater than 20. I was wondering whether water hardness levels between 20/30 and 50 are commonplace somewhere in the world.

  • 1
    $\begingroup$ Try lookin at hot spring where hte mineral content is at saturation. $\endgroup$
    – John
    Dec 26 '18 at 15:12

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.