WAY too small! Tangs love to swim, and the RSM won't cut it. Fish will be perpetually unhappy. Even the tanks we all say are okay (6' or bigger), are really to small for these fish, considering their "natural" home.

We have a responsibility to the beautiful creatures we "adopt" to care for the responsibly, and sometimes that means putting the animal's interests ahead of our own preferences. There are many beautiful fish that will be very happy in a RSM - stock accordingly and both you and the fish will be happier for it...