I want to make an aquascape for a 120g, 4x2x2 with arches and pillars so fish can hide under and go thru things. I don't want to just stack rock. If I use live rock, how do I bond them together? Take them out and use mortar? Will that kill live rock while mortar sets up? Or is there something that sets up underwater? Will dry rock be easier? And, are there LFS's with supplies (not rock) for aquascaping? Any help is appreciated.