a bright flash from the bathroom caught my eye.
The jar was now well boiled out, and the scum near the bottom of the jar had made a weird “sculpture” lattice formed by the current, bubbles, minerals etc., and it was glowing bright incandescent white-orange.
I find this interesting! A white flash, followed by a glowing white-orange light material at the bottom.
I'm guessing that the house fuse (presumeably 15 amp) blew at the time of the flash, unless you know otherwise. I assume that the bluish green patterned sludgy film mostly at the bottom was due to the fairly mineral rich water supplied to your home. I also assume that the copper wire was in contact with the bottom, unless you know otherwise.
Anyway, i applaud the true spirt of adventure and truth seeking at an early age
Here's a video of a guy electrolysing different water sources including tap water, showing the particulates forming in each. Note the blue green in the tap water. (Please ignore his conclusion that this demonstrates the ill effects of such water!)