i dont thing the rack will move once the tanks are filled. the rack is pretty heavy and is already very stable as it is.
i also like how the lights are hidden, but they might come down and sit on top of the tanks if the lights dont end up being bright enough. i'm planning on building up the substrate a good 3"-4" so that should help.
the shelf was made by my dad and me. turned out a lot better then i thought, but looks better in the pics. it is paint not laminate.