rock wall, glue it or egg crate?

[nanmer]

After considering the weight problem cement will really add to the issue. The 180 gallon is made out of really thick glass, add cement and it will weight too much. I just picked up a custom 58 gallon tank and I think I will play with the cement idea with that one. I can easily use it as a cure tank.

I have seen the back of toilets being used as a cure for man made rocks, it is a brilliant idea. I would need a really big toilet to cure enough for my 180 gallon tall!

I have been told that the "great stuff" spray foam is probably sufficient to use since I will be covering all of it and the VU rays will not hit it. Is this correct or should I find black pond foam?

I really appreciate all the great info. I think I may have to become a picture taker and chronicle the build once it gets past the thought stage.