My current tank was made with 30/70 LR from a previous smaller aquarium I had and dry rock that was purchased for the upgrade. A year later, I couldn't tell you which is which. I have coraline, featherdusters, rock anemones, sponges, mushrooms, micro stars, and pods that have migrated to the dry rock. I would now consider every rock in my tank to now be live rock. I have feather dusters on the glass of my sump but I don't consider it live glass. Most of the cool hitchhikers I've gotten over the years have been from the rubble or plugs that the corals I bought were mounted to.