N.M. Code R. § 20.3.15.1523
B. The licensee shall measure the pool water conductivity frequently enough, but no less than weekly, to assure that the conductivity remains below 20 microsiemens per centimeter. Conductivity meters must be calibrated at least annually.
[5/3/1995; 20.3.15.1523 NMAC - Rn, 20 NMAC 3.1.15.1523, 4/15/2004]