To soon???

[rusty]

I have a question. I had a 30 gallon reef tank up and running for about 10 months 2 clowns, 2 yellowtail blue damsels, 3 green chromis, some softies,couple lps and some sps. In swithing over to my new 114 gallon I took the contents of the 30 and switched them to the 114,water, livestock and liverock and a brand new decorative sand bed. I have all my fish and coral in the tank would adding another fish like a small yellow tang be too soon? The switch was made a week ago. I was told it was by the LFS and before I buy the fish I want to be sure... not sorry that I did.