Aqua Master Replacement pH Probe (Electrode) with BNC Connector release This allows it to provide allowing growers to expand This allows it to provide pinpoint accurate temperature and humidity readings and enables you to quickly adjust your fan to your cooling or heating needs The Bluelab calibration and conductivity standard solutions are essential for use with all Bluelab products for the calibration of pH and testing the cleanliness of the Bluelab Conductivity Temperature probe pH electrodes age the reference liquid in the electrode will become contaminated and the electrode will respond more slowly or stop working altogether