many if not all corals eat phyto but you probably dont need to add much if any depending on what you are keeping. Most LPS that are going to be fed should be fed zooplankton or meaty. Many SPS and Leathers are phyto feeders. Between lighting and nutrients they take in thats already in the water you often dont have to feed corals. many LPS will grow alot quicker if fed meaty foods. Can mess up water quality very quickly adding phyto.
BTW why are you asking?