I find my chromis will eat small items such as flake and frozen spirulina brine shrimp. I do feed mysis to the tank (I have larger fish) but they sometimes have issues with the size and will only eat the smaller items (or sometimes just spit them out).
As for the rest of the tank, they will feed on the leftovers and what is floating in the water column. If you like you can feed stuff such as reef roids, reef chili, or ocean pearls or something like that to supplement the corals diet but for the most part light will get the job done. Adding any extra food just for the sake of the corals may just get you lots of algae so at this point I would say just keep feeding the fish for now and the rest should do fine.
