Thank for everyones reply. he's looking terrible this morning and I noticed one of my shrimp picking at his skin. I'm guessing by tonight he'll be 100% gone.
Usually these guys aren't hard to keep, I'm guessing either one of my fish or a shrimp picked at him.
I have 260watts of PC light and needed to have him somewhat towards the top, he never really thrived in the sand bed for me.
weird....