ive kept a niger, sargassum, blue throat, clown, humu, whitetip, undulated, and R. bursa. ive successfully fed them many things including krill, shrimp, kalamari, octopus, muscles, clams, shelled cockels, angel formula (made up of sponge), mysis/brine spirolina, spirolina flake, new life pellots, and other smaller pellots i have.
all my fish love nori soaked in garlic for about 20 mins also!
right now im housing a clown trigger, humu trigger, emperor angel, fiji puffer, and snowflake eel together... the only reason i feed the brine/mysis is because the angel loves it.
changing it up as much as possible is best for fish.