If the fishes feed mainly on algae (e.g. surgeonfish ) then green food or feed with high vegetable content should be constantly provided. Some marine fish feed on plankton which is also available as a fluid solution.
Although most of the corals feed from light, the corals feed is highly advisable. We have coral feed available for SPS and LPS which promotes the growth, colour and health of corals. Moreover you will also find bacteria solutions and bacteria feed which promotes a stable tank biology.