Upgrading from a 55g FOWLR to 110g softies, LPS. Have never attached my rocks to each other. I like that I can move things around. I’m concerned about structures falling over or slumping w corals. So, I’m putting them straight on the glass and putting the sand overtop. Instead of sand 1st, then rocks. Figure this will prevent landslides due to digging. Concerned about scratching the bottom of the tank so considering a pvc sheet or something under the rocks. Anyone else do this or am I being paranoid?