...and the tank overflows.

I heard some water dripping and happened to glance over; water was almost to the top of the display tank, and some had splashed out. I don't know if the ATO float switch got stuck, or something backed up in the overflow box, but I had to act quick to drain water out of the tank, stat.

After I shut off the return pump, i drained some water from the sump. I went to investigate the overflow box. With my hand in the water, i touched my arm to my light fixture and - Zaaaap! I got a nice little surprise. It wasn't a full jolt, but it was a tingle. At this point, I realized something else was very wrong.

Upon closer inspection, I could see that water had dripped out of the tank from the side, casually cascading onto my electrical components, all conveniently located in one place. My GFCI was soaked, and dripping water, and there were splashes on other components. To be safe, I unplugged everything, and said goodbye to the GFCI. I'll be running everything in emergency mode to see what I can salvage.

I'm seriously rethinking this tank setup. Right now, anything looking DRILLED is looking good...