Aponogetons and DIY substrate heating
I'm sorry to hear that your foray into substrate heating
didn't work out. From your description I would guess that
the problem wasn't caused by a fragile (broken) wire, but
by a failure of the insulation at some point. Probably one
of the connections was not properly sealed, and some current
started flowing to ground through the water. I don't remember
what method your friend used to seal his connections; I used
several layers of heatshrink tubing on my setup, and it has
worked very well.
By the way, that Bolbitis you gave me is growing like crazy!