Is this BJD? Or something else like algae?

[AydenLincoln]

I noticed it’s hard! And stuck on the skeleton unlike the slimy texture of brown jelly disease. I’ve lost many great corals to brown jelly disease before. I think I introduced one bad coral and then I accidentally spread it around my tank but this was months ago. And my tank is a few years old and otherwise doing really well.

 

[crazyfishmom]

That head in the right looks like it’s getting ready to bail. In general I don’t think the band is BJD, just looks like maybe algae on the skeleton which is also not great since algae doesn’t normally cover healthy tissue.

 

[AydenLincoln]

Any other thoughts?

 

[unclejed]

Any other thoughts?

It does appear to be necrosis. Read this;

Coral Tissue Necrosis - The Mystery of RTN and STN

Many hobbyist theorize about what causes this disease, but is there a common thread? Here's what we do know about coral tissue necrosis.

www.bulkreefsupply.com