3701-31-04 (B)(1)(c) / Minimum disinfection residual shall be maintained as required.
Critical Chlorine disinfectant residual was less than 2 ppm for the spa
Do not operate the pool when the disinfectant residuals are less than what is required. Ensure the chlorine disinfectant residual is at 2 ppm or above prior to placing the spa back into operation.