Since we have changed it to farm animals what about a pot bellied pig? How many of those do people keep in there apartment? I consider a Regal Tang a pot bellied pig, after you keep one for several years unless you are feeding they typically sit inbetween live rock and camp out.(Too lazy to Graze) I would not even think of putting a half inch regal in a 200 gallon tank. I would start him/her out in a small tank by themself or with docile fish grazing on live rock and what ever you feed. But as years go by you will need to move them into a larger tank or trade them in for another baby and start the process over again. And that is my two bits