birds nest issues

[ScubaSteve]

Ahh, ya... This is the cruel joke if birdnest corals. They die from the inside put because the outer branches shade the inside so much that the polyps on the inside die. Unfortunately, if there is anything that can cause an infection, or if the colony has border line health to start with, the areas that are dying undergo RTN and the whole colony goes up like a lit match.

I had a colony the size of a cantaloupe die exactly this way, though I have no idea what caused the RTN. Unfortunately once this starts there isn't often much you can do to stop it. I highly recommend raging up the colony to save the living parts and get rid of the diseased. Start fresh. I found that once my birdsnest started rTNing a whole bunch if other colonies began to follow suit; once I got rid of the dying bits of the birdsnest all was right again in the world.

Also check your alkalinity. I've found that alk swings are usually the trigger fro all of this. I can now tell when my alk is low based on what the birdsnest is doing.