TheRock wrote:

I've read that they are really only a threat to crustations and escaping out
the top of the tank.

They'll eat any fish they can swallow. The F&S website says "It can be housed
with some invertebrates, like anemones and corals, but not crustaceans." They
also confirm that these guys are escape artists. I've read claims that these
guys have gone down an overflow and escaped from the sump.

How fast do they grow ?

Typically 6 or 7" a year.

George Patterson
Forgive your enemies. But always remember who they are.