Sorry for not making the wink obvious enough and confused you.
With sufficien lighting, the mushrooms and leathers should do well without target feeding. They are not very demanding when it comes to light requirement either, and that's why they often are some of the beginner's corals that many people suggest.
Regarding your question, if they expanding well, and are growing, they are getting enough to "eat." Again, they are mostly photosynethetic, so you don't have to target feed them.