Purple wall hammer

[Sctip]

Does anyone have any idea what this could be?

It's been getting bigger and just curious if anyone could shed any light on this. I would hate to see this coral regress after nursing it back to health.

 

[zombie]

Looks like it might be fighting with another coral. Are there any corals nearby with long stringers (acans, favia, etc)

 

[Sctip]

It's not by any aggressive corals.

 

[Haddonisreef]

The gps could be the coral causing this response

 

[Miah2bzy]

The gps could be the coral causing this response

+1 The gsp in my tank killed a monti frag I had placed too close to it.