What is causing this black stuff?

[ScubaFish802]

I am noticing this morning there are some tips of this Sinularia which appear to be turning black and dying.

I am planning to move it, but I am wondering if this is happening because of light intensity, being stung by nearby coral, or something bacterial, etc..

There is a hammer directly in front of it's current location, there is a gap of a few inches between them (the photo makes it look much closer as the hammer is in the front of the tank while this coral is in the middle) but it is possible at night it is sending out longer sweeper I suppose.

Around a month ago I upped my light intensity by ~10% overall. No other softies are reacting badly however.

 

[blaxsun]

Could be from being stung. Any nippers (fish)?

 

[Cheezle]

I read somewhere that those black polyps mean it has a bacterial infection but I was never able to verify it.

 

[ScubaFish802]

I ended up finding a longer sweeper from the hammer stuck directly to the branch where some of the blackness was later on - forgot to follow back up - it is in more light and is still already looking way more extended overall. I guess I didnt realize just how much range they had