Aponogetons and DIY substrate heating

Hi Karen,
  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!

Glen Osterhout