For bare bottom aquariums, the biggest potential hazard is a live rock avalanche that could damage the exposed bottom of the aquarium. While this may be an unlikely scenario, it’s still a potential issue. Fortunately, there are several things folks in the bare bottom crowd can do to prevent such an event. For one, secure each and ever rock with the use of acrylic or nylon rods, zip ties, epoxy, and live rock cement/mortar. Not only will these items allow you keep falling rocks from ever happening, but they can also help you create amazing rock structures. Another option is to use a piece of starboard (also know as kitchen cutting board) in the bottom of the tank. This white material is resilient to rock slides and also makes a great place to glue frags. Coralline algae and other stuff will also grow on the cutting board material, eventually making it look more natural in the tank.