barnacles

What is killing my frags? It is hard like barnacles. I dipped the corals in Revive and tried peroxide. I did water change, but these white dots keep multiplying and my mixed reef is dying. Is this barnacles? I don't know what to do. It is in my 100g tanks with fish and invertebrates. I have both...

What are thosr "hands"? Are they harmless? How to contain them?