My wife and I had a diamond Goby for a while, and we just loved it. I didn't realize that they needed small sand to live in and I think that the crushed coral that we had in the tank was too big. Anyway lesson learned. I was wondering if a Ten gallon would be too small for one Diamond Goby, and maybe another smaller fish, or shrimp of some sort. I am going to set up a ten gallon and use what corals, and live rock I can out of my 55 gallon. anyways just wondering if the diamond goby would be small enough for the tank.