Alkalinity to Milliequivalents Conversion

Converts alkalinity (or hardness) reported as mg/L as CaCO3 into milliequivalents per liter, placing all species on a common neutralizing or reactive charge basis for softening calculations, scaling indices, and charge balance.

$$meq/L=\frac{{\text{(mg/L as CaCO}}_3)}{50}$$

Variables

Symbol	Meaning	Unit
meq/L	milliequivalents of reactive charge per liter	meq/L
$mg/LasCaC{O}_3$	concentration expressed as calcium carbonate equivalents	mg/L
50	equivalent weight of CaCO3	mg/meq

Worked example

For alkalinity of 100 mg/L as CaCO3: 100 divided by 50 equals 2 meq/L, which equals 0.002 eq/L.

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Part of The Blueprint of Water