Nothing they get everything they need photosynthetically from the light. You have a strong light over the tank right?
But!!! You can feed them if you want.. a little reef roids here and there can get them moving. I've seen them take mysis shrimp before, hairy mushroom and a toadstool.
I can't make an honest claim. While I do have all types of healthy coral, my green digi is displaying excellent growth, my algae is also a top contender. It's like Michael Phelps and that other guy from the last summer games. But healthy sps is healthy sps
It's... something!!! Alright. I'm opromisticly sour... the coral is all thriving so aesthetics can wait.Join the algae club! I have some in my tank too but it provides a natural food source for my angel. As long as it’s not out of control it’s not really bad imo.