Quote:
Originally Posted by GoFish
What would be causing it? Perhaps everything 
Could be "Magnetic induction" Had noticed the same issue in 2014 and discussed it HERE. Gets complicated. I no longer test for stray voltage, probably should but still don't know what to do about it |
Lots of good info on that link but it's not stray or induced voltage from the pumps because they were all unplugged when I tested.
I don't think the voltage is enough to harm anything but I need that ph probe to stay calibrated and working properly to control my calcium reactor. I'm not sure if it's because the controller plug in only has 2 prongs but from the googling I've done it looks like that's the right plug in.
Another strange thing I noticed is when I hook up my laptop to the controller while everything was plugged in, the voltage dropped to 2 volts. That was with the laptop charger plugged into the laptop. If I unplug the laptop charger it's jumps back up to 20. Could it be because the laptop being connected to the controller has a 3 prong plug in and takes the voltage from the controller?