Slow growth and pale color in some frags why?

[ScottB]

Is a 60 gal cube big enough for that fish?

For a juvenile sure, but you would have to rehome at some point. I got about 3 years before rehoming mine out of an 80G shallow frag. I guess a Tomini or Kole tang could stay a little longer. My spotted kole is a good grazer as well.