I have had some experience in the past with black sun corals but was not much successful may be because i was too lazy to feed them daily, but I am a changed man and Will Dedicate my self to feeding this sucker daily. Probably with marine snow and cyclopezz.
When i target feed cyclops i use the sea squirt by kent. It extends for deep tanks and is pretty handy. For bigger food i use the turkey baster. You can get the nose in different sizes. Shut down your flow as well to give them time to eat.
Or you can use the bottle method. Cut a 2 liter soda bottle and cover the sun. From the bottle opening squirt the food. This will prevent any fish/shrimp from stealing their food.:chef: