Charge Balance

Definition

The relationship in which total positive reactive charge in water must equal total negative reactive charge, both conveniently expressed in milliequivalents per liter.

Because one meq/L of positive charge balances one meq/L of negative charge, expressing all ions on a meq basis lets cations and anions be summed and compared directly. Reporting hardness ions like calcium and magnesium as mg/L as CaCO3 puts them on the same equivalent basis as alkalinity for these relationships. This common basis underlies softening calculations and scaling indices.

Related concepts

Hardness as CaCO3 · mg or L as Calcium Carbonate · Milliequivalents per Liter

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Part of The Blueprint of Water · 📏 measurement