29 biocube Rock wall

I built one a while back for a 60g cube using egg crate, pond foam, and zip ties. If you want more info and pics, shoot me your number.

 

Thought about doing this to my 60 gal. Rimless, but don't want to destroy it!

 

FFisbrain has a rock wall in his 150. I think he got the peices already made from someone in des Moines area or something like that. He could point you in right direction.
I actually just read a tank thread on reef2reef about someone using egg crate and pond spray foam. And when it set up a little he sprinkled sand and rock rubble on it. He said he had to use the outdoor pond foam cause it was UV resistant. I also heard of people using sand and some sort of mortar to make rock walls. You could probably search on reef central also.