Hi aprillynd and

to TR.
I agree that garlic is a good appetite stimulant. I thaw my food, rinse it and then soak it in garlic. I've always used garlic extract but I have read that you can also use freshly chopped garlic.
It sounds like you bought this fish and put him straight in your display tank. It is always a good idea to quarantine anything (fish, coral, invert) you add to your tank. This gives a new critter a place to get over the stress of shipping and gives you time to closely observe them. A
QT tank allows the new inhabitant time to learn to recognize the things we feed as food and to eat without competition. It also prevents you from introducing disease into your tank.