I think I will lower alk to 7 too. Right now its around 8.
Birdsnests are particuarly sensitive to many parameters....an alk spike, a significant change in flow, too much time out of water, a nutrient shock....and they might RTN. Be prepared to try again if this one doesn't make it. Once they're established and the tank is stable, they're REALLY fast growers and pretty resilient.
How stable are all these parameters in your system? Any significant time out of water? Are these corals being moved around? Are lights being changed?