CORAL IN TROUBLE PLEASE HELP

[YandyRiv]

good afternoon,

So i bought this coral few months ago and recently i noticed that the some of the heads started disappearing and this whitish crust started growing. Any ideas what this can be

Will dipping the coral with revive help?

 

[Fishy212]

Could be pests... something eating or irritating it. Do you have peppermint shrimps? Without additional information it kind of difficult to help.