A real water analysis balances, so Σ cations (mEq/L) ≈ Σ anions (mEq/L).
An error above ~5 % usually means a typo, a missing ion (nitrate, potassium,
silica) or an alkalinity entered in the wrong unit, and the brewer should
know before a pH prediction is built on it.
Cation/anion charge balance error, %.
A real water analysis balances, so
Σ cations (mEq/L) ≈ Σ anions (mEq/L). An error above ~5 % usually means a typo, a missing ion (nitrate, potassium, silica) or an alkalinity entered in the wrong unit, and the brewer should know before a pH prediction is built on it.