This is as far as the sun coral will open. Had him four days. Just wandering if he is getting food or is it still going hungry with no polyps out to grab the food?
It needs to open the polyps in order to gett food. Test for a week to give a lot of frozen adult artemia (or frozen freshwater cyclops) at a given time - best may be just before your light turns off. Be sure that your fish had get their food first. I have a lot of sun corals in my aquarium - the only food I use is frozen adult artemia (brine shrimp) and freshwater cyclops from Ocean Nutrition - a short video - note the catch at 1:17
Thanks for the advice, I have been feeding the fish first that gives food in the water for it to react then trying to feed it small amounts over the course of 45 minutes and it is coming out a little bit better. I have been using cyclopods and mermaids delight.