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Re: Hardness in ppm

Neil Frank wrote:
> When a test measures total hardness and separately presents measurements of
> calcium and magnesium, it seems that the units for hardess are not presents
> as CaCO3 or CaO. If it is, does anyone know what it means to present the
> magnesium compound concentration in terms of equivalent Calcium or Calcium
> carbonate?

I think this is always done on an equal equivalents basis.  In words, when
magnesium is expressed as its calcium equivalent the number is the weight
of calcium that would carry the same electrical charge as the weight of
magnesium that's actually present.  It amuses me that someone, sometime
thought this system actually made things easier!

One equivalent of magnesium is 12 grams.  An equivalent of calcium is 20
grams and an equivalent of calcium carbonate is 50 grams.  So to convert
magnesium as the equivalent calcium to real magnesium you multiply by
12/20.  To convert magnesium as CaCO3 to real magnesium you multiply by

Roger Miller