I have a Nano 12DX that I've thought about starting back up. It's been empty since I upgraded to my 55 last summer. I was thinking about turning it into a tank strictly for small gobies, zoo's and maybe some mushrooms. I want to cut a piece of eggcrate to fit the back wall, then cover it in something like Plaster of paris and then affix small pieces of live rock to it and let it dry and "cement" the rocks to the eggcrate. I think it'll be good for making some really cool little ledges etc and this will leave a lot of open room for the Zoanthid Islands. Has anyone done something like this and what did you use if you have. I thought about Plaster of Paris, but don't know if it's safe for use in an aquarium. Any help would be greatly appreciated, thanks!