You definitely won't have to wait a year to place livestock in your tank. There are just certain fish, corals, and invertebrates that are more sensitive than others. Keep doing your research. After your tank cycles, you should be able add your first fish.I will definitely wait to add ANYthing to the tank before it is well established, even if that means looking at an empty tank with a rock in it for a year. I like the idea of urchins or starfish too. Would those be able to thrive in a 29?