It depends what fish you have. Tangs etc require seaweed in their diet, predators such as puffers, lions will require stuff lie frozen fish, live river shrimp, krill, cockle etc.
I feed my clowns:
Live Brine Shrimp (all tanks get it once a week)
Frozen Brine shrimp with spirulina
Frozen Daphnia (every so often)
Frozen Mysis
Lobster Eggs Occasionally
Cyclops
Live River Shrimp (if its small enough)
Frozen Krill
king British Flake with various freeze-dried shrimp
Ocean Nutrition Formual 2 (green one)-will change to reef flakes when i can find some!
For the anemone i give it a frozen fish (silverslides) twice a week...just hold it near its tentacles and it will grab it...great to watch
IMO if you already have an anemone, you really should know what to feed it. If you dont and you want one, wait till your tank is at least 6 months mature.
LR wise, your dont need to feed anything, there are chemicals that can be used to incourage coraline algae growth etc.
I put live plankton in my tank every other day for the corals, feather dusters etc...i directly feed the corals like frogspawn , hammers etc frozne daphnia, myisis, brine shrimp, cyclops and plankton...all mixed in a jar together.
OK?