Sorry Tim, but you are all alone on thinking that a Tang in a 30g is ok. Yes they are kept in fish stores in tanks that size, but stay there a couple weeks a most where they either go somewhere else or die in the store. I wonder how many more would live if they were kept in bigger tanks. The logic of a Tang being small so it is ok until it grows is flawed. Tangs swim a LOT in the ocean. Whether big or small. Put one with no room to roam and it gets stressed. My brother in law had a Yellow Tang in a 55 that was less than 2 inches. The poor thing paced all the time until it died a couple months later. Tiger's need large areas to live in too. Do you think a 200 lb Tiger needs less than an 800 lb one? How about a dog? Would you keep a puppy in a closet until it got bigger? I feel it is a bad idea to encourage new ones in the hobby to push the limits. They are usually so excited and under informed that they will make bad choices anyway. We all did when we started. It is our responsibility as experienced hobbyists to encourage patience, restraint, and proper methodology. That is not to say that we don't learn new methods or ways of keeping these animals. But something like big fish in a small tank will never change.