i HAVE A YELLOW TANG, CORAL BEUTY, PAIR NEMO, AND A SIX LINE WRASSE. Can I add a dory/blue tang to my tank? 55gal with protien filter, tons of rocks and cleaning crew. 20% water change every 2 weeks. I really would like to add a dory to my tank but I wonder if is ok. I;ve heard that they need lots of room but i ALSO HEARD THAT IT WILL BE OK.