I'm going to be setting up a tank in a little while. So I have a ton of questions. I want some Pistol Shrimp maybe a watcher goby too. My question is what do I want to use in the bottom of the tank? My local stores say to stay away from sand (which I know you guys like) to much trouble. Go with crushed coral that would be better with shrimp. Truthfully I'm a little confused on what to do. Thanks for any help.