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conversion from ppm CaCo3 to dkh or meq/l?


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after some intense digging around i just found it...


The various units used for alkalinity are themselves cause for confusion. The clearest unit, and that used by most scientists is milliequivalents per L (meq/L). For a 1 millimolar solution of bicarbonate, the alkalinity is 1 meq/L. Since carbonate takes up two protons for each molecule of carbonate, it "counts" twice, and a 1 millimolar solution of carbonate has an alkalinity of 2 meq/L.


A unit that is used by many kits and some industries involves representing alkalinity in terms of the amount of calcium carbonate that would need to be dissolved in fresh water to give the same alkalinity. Typically, it is reported as ppm calcium carbonate. Of course, it has nothing to do with calcium, and there may be no carbonate in the water at all. Nevertheless, it is frequently used. Since calcium carbonate weighs 100 grams/mole (100 mg/mmole), then a solution that has an alkalinity of 100 ppm calcium carbonate equivalent contains 100 mg/L calcium carbonate divided by 100 mg/mmole calcium carbonate = 1 mmol/L calcium carbonate equivalent. Since carbonate has 2 equivalents per mole, this 100 ppm of alkalinity is equivalent to 2 meq/L. So to convert an alkalinity expressed as ppm CaCO3 to meq/L, divide by 50.



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  • 4 weeks later...
Originally posted by Physh1



It is the weekend and not everyone decides to spend it on the net.



Or spend it checking dates either. ;)




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