pH Electrode - Double Junction

The Neptune Systems pH Electrode - Double Junction is an extra sustainable and accurate pH electrode. Replace your pH probe or add another for another tank, calcium reactor, etc. Buy this probe if you are buying the Apex Lite, because the Apex Lite does not include a pH probe. You can use this probe as a back up probe or to replace a worn out pH probe (it is recommended to replace your pH probe every 18 months). This probe can be used when you adding another tank to your system and purchased a PM1 to do so.