Checking for stray voltage confusion????

[EZMAC114]

I checked for stray voltage in my tank the other day and it read 91v so I started unplugging pumps and heaters...every time I unplugged something the voltage would go up. My LFS should me a ground probe to see if it would help and with the ground probe hooked up it reads 119v. Am I doing something wrong or just understanding how this works incorrectly??

 

[EZMAC114]

Well I was just informed that I don't have it plugged into the proper GFCI outlet so that could be causing it. And I can't change they type of outlet because it is right behind my tank brace

 

[Reefing Madness]

[video=youtube;ffDctOPRS6c]http://www.youtube.com/watch?v=ffDctOPRS6c[/video]

 

[EZMAC114]

I watched that video the other day and my results do not match his lol. I might try a different meter