We have a blastomussa wellsi in our tank that seems to be having issues. We have had it for 5 months and it seemed like it was doing great until about 2 weeks ago. When the problem started, it looked like the center of one of the polyps was burning out. Then it started to spread across the bottom of that polyp and toward the right side. When the blasto puffs up completely, you can hardly see the problem area. We have included several pictures so that you can see what we are talking about. The white part that we are referring to is soft tissue and it isn't hard like the polyp's skeleton.
Tank Specs:
46 gallons
4x39W T5 Light
All water measurements well within normal parameters
Picture 1 = Blasto's Placement in Tank

Picture 2 = Blasto semi-detracted

Picture 3 = Blasto completely detracted

What is this? How do we stop it? Is the whole colony going to die?
Tank Specs:
46 gallons
4x39W T5 Light
All water measurements well within normal parameters
Picture 1 = Blasto's Placement in Tank

Picture 2 = Blasto semi-detracted

Picture 3 = Blasto completely detracted

What is this? How do we stop it? Is the whole colony going to die?