Hanna Electrode Cleaning Solution- 500 ml
We recommend calibrating digital pens weekly for readings you can trust. It's best to keep pH electrodes wet, and manufacturers recommend using Storage Solution to do this. Calibrate pH meters at both 4.0 and 7.0 to give your pen a "slope" reference. TDS pens must be calibrated with the appropriate reference solution based on brand and type. The Electrode Cleaner is for pH electrodes only. Use rubbing alcohol for TDS electrodes.