The lps nps are pretty easy especially in a tank that is designed for them in mind. Nothing to bother them or steal food such as shrimp, crabs and fish. The lps under low light or no light will open more often and they will eat just about anything if its the right size, mysis, brine shrimp, some pellets. The stuff with small polyps are more difficult like most of the soft nps, sea fans and gorgs. These may need live feeds to get the polyps to fire things like live rotifers or small pelagic pods. Some will except a wide range of prepared feeds as well but a lot wont, It takes that swimming motion or the struggle of intended prey items trying to get away to actually cause the polyp to close and take in the food. Kind of like a venus flytrap some will accept a dead bug but most wont because the hairs on the "mouth" are not being triggered by motion. I have no absolute proof that they do or dont eat phyto my guess is they dont but it does feed the stuff they will eat so it cant hurt to add some.