[craigwmiller]

Good thought possibly static/etc from the bubble velocity/etc...

so I just tried it - I removed the intake venturi from the pump (stopping all air from being drawn in), and let it run a few minutes to calm down -- no difference.

I also then tried moving the PH probe around the sump (and into the display) to rule out distance from electromagnetic fields/etc -- nothing.


I think I've narrowed this down to an induced voltage from the EMF from the pump feeding the skimmer. With my volt meter in DCV mode, I have a potential of 167 millivolts from the tank to ground with the skimmer running, and 0 millivolts with the skimmer unplugged. True this EMF isn't creating DCV, but there is still some detectable as a 'potential' so the skimmer motor is very likely unshielded.

I've done conductivity testing from the tank water through to all prongs of the skimmer cord (and between them) and the impedance is at least 2 million ohms - so let's say there's no connection -- so this must be EMF.

Now, I could definitely just be talking out my A** and chasing a solution that makes sense in my mind (after all the troubleshooting), but it would seem this explains it best (in the absence of a physical leak from any of the 3 conductors to the tank - as identified by conductivity).


Ordering a new skimmer me thinks. Or at least a new pump.