My platygyra is dying in a corner?

[rozzzna]

I got this platygyra a week ago, but it has started dying in a corner, and it is spreading. Yesterday the spot of dead coral was half the size it is today.

Can I do anything to prevent it getting further? And what could be causing this rapid death?

 

[Reef Bass]

To me it looks like the onset of brown jelly which can very rapidly cover and kill the whole piece. Frag the infected area off taking a good 1/4-3/8 inch margin of healthy tissue off with it. Do an iodine based dip afterwards.

 

[rozzzna]

Thanks, I have fragged it with 1/4" of healthy tissue as well. I hope it will recover