My 300 Ltr (80 US Gal Including Sump) is a mere 12 weeks old and already I have a family of fish doing very well without aggression. The very last 2 fish I wish to add to complete my stock is the Yellow Tang plus 1 other, prob the Regal (Hippo) Tang. My Yellow has been reserved at the LFS for prob 9 weeks and its about time he comes home. Do I put him in before the Regal Tang or later. The Regal is about 2inches the YT is about 3inches. OR at the same time.. please advise