i would try and give him a couple small pieces of frozen brine shrimp or mysis shrimp to see if he takes to it. usually what i do is Cut the cube of frozen food that way you don't waste the rest. If he does not eat any then discard the rest so you don't pollute the tank.
You should post some pictures of course when he starts coming out more.
my dad may be rich but he's a super tight ass! lol i've paid for all my tanks myself with my own hard ernt money! i think he deserves to buy me a new camera haha will deffo be getting one because were going on our jolly's in 6 weeks so need to take holiday piccys