Neptune Double Junction pH Probe

ThE Neptune Double Junction pH probe is designed to be used with your Apex controller to accurately measure the pH in your reef aquarium.

This product is also a replacement for the discontinued lab grade pH probe no longer produced by Apex.

Neptune Double Junction pH Probe Features

• Measures pH from 4.0 to 12.0
• Quality manufacturer
• Stays calibrated longer
• Longer life
• Replace every 18 months

The Apex System includes probes for Temperature, pH, ORP, and Salinity.

The pH and ORP probes are now double-junction (lab grade) as well. This means they hold calibration longer and have a longer lifespan than single-junction probes.

WHAT’S THE DIFFERENCE BETWEEN DOUBLE JUNCTION AND SINGLE JUNCTION PROBES?

Single junction probes put the reference electrode in direct contact with aquarium water. Over time, the junction will slowly leak aquarium water into the electrolyte. This changes the accuracy of the probe and requires more frequent calibrations.

Double junction probes place a second vessel inside the main electrolyte with a second internal junction. The means that even when the aquarium water eventually begins to make its way in the first compartment, it still has to go through the second junction to contaminate the electrolyte surrounding the reference electrode.