Help!!!

[Seagars]

need help in IDing this issue and do i need to be concerned and how do i fix if so. Greening at base of coral.

 

[Reef Breeders]

How old is your tank, It looks like the frag is completely bleached, and that is algae growing on some of the tissue that died.

 

[Seagars]

about 4 month old
29g biocube hqi and all water test have been perfect
how do you fix it? if you can

 

[Reef Breeders]

What do you test for? Results? It can solved, but it takes time