vitz":3dvubfw1 said:while the coral will probably do equally well on a rock as it will on the substrate, the main danger is from the coral toppling itself over and falling off the rock when it expands, or getting knocked over by a crab, turbo, etc
if you can glue or epoxy it it should be ok, though some more purist minded hobbyists may look at ya funny when they see it elsewhere other than on the substrate