I have one in my 120. Still small at about 4 inches with hints of juvenile colors still present. Probably one of the shyest angels, but they become a bit more outgoing in time. IME, making sure it is the alpha fish in the tank will go a long way towards having it acclimate well. Give it a well rounded diet to include lots of meaty foods; chopped mussel, shrimp, clam, mysis, plankton, pellets, nori, occasional flake food. Mine eats everything. What size tank is he going in?