I have a large yellow tang (4-5") that came with the 180 gallon tank I bought. I was told it would be hard to add new smaller fish with him in the tank. so when I move the 180 tank he ended up in a temp tank thats 55 gallons. I would like to move him back in the 180 but I still would like to add more fish soon like a small blue tang,green mandarin,and some firefish. In the 180 is 7 green chromis, a diamond watchman, and a coral beauty. Just interested in everyone's thoughts and opinions.