Generally when you stick foil with your uth it is the uth that is sandwiched between the foil and the glass of the tank to make sure all the heat is reflecting upwards and you're not losing heat thru the bottom of your uth. It would be shiny side towards the uth plus you would likely want to poke a few holes in the foil so the uth can breathe.
Ah yes the relocation factor. I didn't think of that Tara... thanks for the reminder. It actually does kind of matter a little as one side will be more "non-stick_"than the other but given the application being used here I don't think it'll matter.
LOL The relocation was what I was looking for. I ended up sticking the dull side to the pad. Then I taped it under. The heat is working great. I wish I would have done that with Eggo's tank, but I don't thing he is moving out of the 20 anytime soon. Thanks guys!
I actually think I have the shiney side of the foil stuck onto my heat pad? There was no rhyme or reason to my modification, and mine works fine too Its been like that for a few months, so I hope it wont hurt anything or cause any fires (its attached to a rheostat too).