My opinion is that a Regal is not a good choice for a 90. I've seen a pair of them in a 300gal, and that seemed more reasonable.
I had a medium Naso in a 6-ft tank, and it could bolt the length of the tank in about .1 seconds. Just for fun. (or was it miserable?
)
Now we have a small Yellow tang in a 75. Never seen a happier fish.
