Question for you guys that have or have used double aquarium stands. Recently I bought a few used double stands made of metal for a few 30 gallon tanks I haven't set up yet. The top of the stands don't have anything holding the tank in its place nor is it the type of set up where the bottom edges of the tank surround the edges of the stand, like your typical wrought iron one. So my question is, is the weight of the tank pressing down going to be the only thing keeping it from falling down? How safe is that? I know it's a lot of weight but I would hate to accidentally knock it off and have a disaster on my hands. It just seems not right to me and totally unsafe but maybe I'm over thinking it ?