miniatus grouper question

[MRICKEN1012]

I just got a miniatus grouper and he is not eating (had for 2 days).
I know they are shy at first. I saw him eat at the pet store. Do they not eat very often?

 

[Recty]

Size of the fish matters, the smaller fish need to eat a lot more than the larger ones.

 

[MRICKEN1012]

he is prob 5in