Re: mg/L to mmol/L

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  • Re: mg/L to mmol/L

    I am trying to compare the water hardness posted by my council to the setting on my diswasher
    the council states
    Town water in Caboolture Shire usually contains between 100 and 200 mg/L total hardness

    the diswasher operating instrustions say it is set (by default) to 0.2 - 0.7 mmol/l
  • JohnS
    Moderator
    Long Time Member The Golden Calculator Award Moderator Over 10 000 Posts
    • Dec 2007
    • 10797

    #2
    Re: mg/L to mmol/L

    Originally posted by Neil F
    I am trying to compare the water hardness posted by my council to the setting on my diswasher
    the council states
    Town water in Caboolture Shire usually contains between 100 and 200 mg/L total hardness

    the diswasher operating instrustions say it is set (by default) to 0.2 - 0.7 mmol/l
    The range 100 - 200 mg/L would be equivalent to 1 - 2 mmol/L.

    You may find this article helpful: http://en.wikipedia.org/wiki/Hard_water

    Water hardness given in mg/L is total equivalent calcium carbonate/ Calcium carbonate has a molar mass of 100.087 g/mol. (I rounded off to 100 in the above as the range doesn't seem very precise). Actual hardness may be a mixture of Ca++ and Mg++ ions and measuring those in moles is probably more "scientific."

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    • Unregistered

      #3
      Re: mg/L to mmol/L

      thanks for the conversion units. I also have a dishwasher , a Miele that wants to know Rose bay Sydney levels, Your reply has saved me doing maths. My machine is calibrated to 0.2 mmol while the hardness here is 0.5 to 0.7 so i have more to do
      a great help. thanks you
      mary

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      • Unregistered

        #4
        Re: mg/L to mmol/L

        Great info.

        I also have a Miele and was told the hardness in Springwood is soft below 0.7 mmol/l.

        The factory setting for hardness is 0.2 - 0.7 so you do not need to change any settings or add salt if the water is constantly lower than 0.7. I have done neither and sometimes I get rust spots on dishwasher safe utensils and sometimes a cloudy residue. I use a Rinse Aid.

        I got a website off Allconnex Water seqwgm.qld.gov.au that does monthly reporting of the Sth East Qld Bulk Water quality. The standard is below 2 mmol/L or 200 mg/L.

        Interestingly, Zone 2 Logan area hardness for Jan 2012 is 1.06 mmol/L.
        Zone 3 Redlands is 0.6 mmol/L. Not sure where the bulfk water for our street comes from but I have a feeling it varies as the washing results testify.

        I'm going to add Salt and change the Dishwasher hardness setting to 0.9 - 1.3 mmol/L and see how I go.

        Will keep you posted.

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        • Unregistered

          #5
          Re: mg/L to mmol/L

          Hi, I also have a Miele dishwasher.

          Water in Papakura, New Zealand comes from Ardmore, Hunua falls and is moderately soft, Veola Water told me, 30mg/l.

          If my calculations are correct, this means I won't need dishwasher salt and the mg/l converts to about less than 0.5mmol/l.

          Hope this helps someone in this area.

          Helen

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          • #6
            Re: mg/L to mmol/L

            mmol/l into mg/l

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            • JohnS
              Moderator
              Long Time Member The Golden Calculator Award Moderator Over 10 000 Posts
              • Dec 2007
              • 10797

              #7
              Re: mg/L to mmol/L

              Originally posted by [email protected] View Post
              mmol/l into mg/l
              Divide by the molar mass (which is substance-specific) in grams per mole.

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              • #8
                Caboolture Shire usually contains between 100 and 200 mg/L total hardness


                This indicates the max/Min and averages for SE Qld - with average 12 month. I have a Miele and it seems that most areas average under the 0.7 mmol/l requirements

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