birdsnest "bleaching"

[Reef Tank 2.0]

If a birdsnest is not under a light source, and has not been moved in over a year, what would cause it to start bleaching out?  The tips are also turning brown, polyps have retraced, etc. etc.  It's definitely on its way out, if not already checked out.  All the other corals in the tank are fine.  This is the only one I'm having problems with.

I definitely know it's not the light, so what else is there?

And before you ask, here are my params
tank has been running for almost 4 years

Ammonia - 0
Phosphates - less than 2
nitrates - 5 or less
calcium - 400
alkalinity - 9.0
magnesium - 1380
pH - 8.1-8.2

lights - (3) AI Hydra 26HD

[Heinbaughb]

Do you have a picture? How much flow is it under?


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