I know this is an old post but think it deserves an answer. I have kept clown gobies in the past and plan on adding them to a new build with the possible attempt at breeding them. Their care requirements are basically the same as the other clown gobies (black, yellow, green). They are not as available in the hobby as the others and do cost more but like their cousins they have a lot of personality and add much entertainment in a nano. They only get about 1" in length so a smaller tank is a good fit and you have to protect them from tankmates that would harass or eat them. They tend to hang out near the base of SPS corals but it is not a deal breaker if you don't have them, they will perch on mushrooms, GSP, xenia and other corals. These fish are carnivores so you should offer them finely chopped meaty foods one or two times a day like shrimp, mussels, cyclopeze, etc, just make sure the size matches the small size of the goby.