Possible disease need help please. New pic added

[Rumika]

Hello, I just purchased a candy cane coral and some of the polyps are dying. Last night we same a long thin clear worm extend and the tip was round. On the coral it looks like there is a white web that is around the polyps and there is a whole that leads inside. What should we do? Should we break off the affected polyps or a fresh water dip?
Your inpput would be greatly appreciated.
Thankx