Neptune DOS and PH issue

[Flux Capacitor]

I’m running a DOS to do auto water changes, and today out of no where I’m having weird PH jumping. It took most of the day to narrow down, but I have tracked it to this DOS when it runs.

I can duplicate the issue by turning the outlets for each head on and off. I’ve tried different aquabus cables, isolated the DOS to only have one aquabus connected to it, but the issue remains. Before i purchase a new DOS, has anyone seen anything like this before?

 

[Troylee]

Most likely interference with the ph probe. Try moving your probe to a different part of the sump and keep electrical wires away from it.

 

[Flux Capacitor]

I tired to move the probe wiring, to the point of having it come out of the front of the tank, and directly into the apex. Still was getting the problem.

I think I’ve actually narrowed it down even more to the PM1 I was using. It was where the dos is connected with an aquabus, and was helping extend where the probe was in the tank. If I take the PM1 out of the equation the problem goes away, so am just going to move the probe. Thanks for the thoughts.