I have a 120 gal reef tank - about 220 lbs of live rock. I currently have a Blue Hippo (since July) and he is doing great (about 3-4 inches long). I have room for one more fish and I'm thinking about a Powder Blue. My questions are is my tank too small for a powder blue and will it get along with the Hippo. If anyone has experience with this, I would really appreciate it. Looking for help before I make a mistake (worked too hard to do that at this point).