Anyone out there successfully run a Hydor ETH inline heater with a pH probe? I just set up a pH monitor this evening and am seeing that the monitor reads as expected (~6.5) in the tank when the heater is on, but when the heater turns off, the monitor jumps to a reading of 14.0. As soon as the heater comes back on the monitor moves back to the 6.5 reading. If I unplug the heater I get the expected ~6.5 result.
I had a second unused ETH laying around so swapped out for that one and am seeing the same behavior.
I understand from researching that stray voltage in the tank from equipment can cause these kinds of readings from a pH probe.
Wondering if this is a general issue with the design of the Hydor inline heaters, or if I just happen to have two faulty heaters.