Thanks bud. Enlightened I have become. lol I did have it on the wrong setting, so I will retest tonight, and hopefully narrow down the root cause!

I have one of those multi meters, so thought I would test my tanks, just in case. And to my surprise, my refugium tank has stray voltage. The needle moved quite a bit.

Turns out it is my T8 light fixture sitting on top of my lexan tank cover. There is a bit of salt creep around the fixture, so will have to see what I need to do to fix the problem. Still surprised how that gets into the water. But when I shut it off, the stray voltage is gone, so that is definitely the source.

Thank goodness, my display tank and sump checked out OK. I have a lot of pumps and electrical devices in and around them.

Glad I read this thread, or never would have thought of checking.

Canreef rocks!

well I thought it was my power bar.. nope, its not any of my heaters or filters or anything, so it must be my lights too then, which is weird cause they are all literally brand new! I dont get it