Feeding Problems with my Dwarf Lionfish

I recently purchased a dwarf lionfish and he looks awesome. He is in my main tank right now. im having a little problem feeding him. I usually feed forzen brine shrimp soaked in garlic. i was told he should eat the frozen shrimp but he just sees them floating and doesnt eat any of them. I also saw that some people feed frozen silversides on tongs, but as soon he sees the tongs he hides on a cave.



I also have pellets and flakes but i doubt he would eat those.



I've own him for about 4 days I know it hasnt been that long, but i really dont want to lose him because he didnt eat and i think after 4 days he should be eating by now.



Some advice or ideas?