Bubble on Leptastrea

[Boerdy]

Hi

my Leptastrea John Deere has this strange bubble.What could this be?

 

[threebuoys]

Has it been present and at this size very long?

Could be brown jelly disease. If it is, it will grow very quickly over a matter of hours or a day and will kill the coral. I hope I'm wrong and someone else can identify a less harmful id.

 

[Boerdy]

Hi
maybe 2-3 weeks.The coral looks fine.