I feel like the SPS corals are like hundreds of little mouths just sitting wide open with soft teeth, stuck on the skeleton like structures they are a part of. the LPS corals are like mouths that have evolved to have lips that help hold things into these mouths i spoke of in the sps corals.
This is based off the corals eating anything from the smallest phytoplankton, zoo-plankton, Rotifers, brine shrimp, even whole chunks of krill, etc...both SPS and LPS....
I feed daily but like others said if you see nuisance or even Bubble algae IMO then cut back. I have great skimmer, and dose vodka so it helps too, and allows the feeding to be daily. But If you really think about it coral in the ocean, has access to food at all times, via the sun as well as the many sources provided by local food chains. Only thing about the aquarium is our water parameters have limits let alone water period, considering we are lacing thousands upon thousands of gallons every day that would bring many things to any reef. So the more the better for your livestock, but this could lead to plenty of cost, like a great skimmer, and different supplements, additives etc, but cost and time... and patience is the biggest thing I have learned.