Custom Tank Building

So I'm fairly new to going past the buy the kit for the kids and get serious, and go obsessive with it. I love to fish, hence I love to watch fish. Just bought our first home, and I have a spot that we don't know what to do with, and since I've really gotten obsessed with the whole fish thing I got a wild idea to build a custom tank to fit the spot. So the first step will actually be building the tank.

Here is the catch, the odd place I mentioned we don't know what to do with is above a corner, electric, fireplace. I'm sure there is a way to put down some kind of thermal mat or protection to keep the heat from effecting it if we did use it, though the previous owner told us they never used it, they were personal friends we bought from, so we might not use it at all, but still this may be a stopping point all together. Maybe someone knows something about putting a thermal layer under a aquarium to protect it from heat. Perhaps I should get some opinions on this before I go any further.

 

If it is an electric fire place, isn't it fake, just creating light, & very little heat? More for looks than actual use? I would assume not much heat output from an electric fireplace.

 

Well I messed that up, it's gas, with an electric wall switch. I'm used to growing up with a real wood fireplace so all this fake fireplace stuff to me just seems "electric" lol. But no, it has a pilot light and runs on gas, just has the electric wall switch to turn it on.