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Re: equivalents
Just a follow up note here as it has been pointed out that my
discussion of equivalents neglected to mention that when we are
discussing cations like calcium and magnesium the convention is to
take into account the charge number when discussing concentration of
these ions. Calcium has a +2 charge so 1 equivalent of calcium ions
is the same as 2 equivalents of positive charge. By convention
hardness is discussed in terms of the amount of positive charge
contributed by both magnesium and calcium. Magnesium contributes 1
positive charge and calcium 2 for each individual ion of the
respective elements. So by convention the hardness figures also take
into account the charge contribution. So in my example in the first
post, 40 mg/L of calcium is equal to 1 meq/L of calcium ions, but
equal to 2 meq/L of positive charge/general hardness.
-Greg Morin
--
Gregory Morin, Ph.D. ~~~~~~~Research Director~~~~~~~~~~~~~~
Seachem Laboratories, Inc. www.seachem.com 888-SEACHEM
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