Shy Flame Hawkfish?

[dc4]

I just picked up a flame hawkfish from the states and it seems pretty shy so far, only hiding at the back of the tank peering throughs the holes of my rock. All the ones I have seen in other tanks have been very interactive and perch out in the open watching things go by. I know that not all fish are the same but for those that have a flame hawkfish, how long before they got comfortable enough to come out into the open?