I have some black sun polyps ... They took awhile to get cozy in my tank .. About a week and a half before they opened full ... Feed them lots in the beginning .... And when they get happy feed them 2 to 3 times a week ... Try to make sure every head gets some food ... I have to feed my cleaner shrimps before I feed the sun polyps ... Or they just steal the food from the sun polyps ...a fun and rewarding coral .. Good luck and enjoy
