acclimatize coral?

[Aquattro]

Yup, they need some sort of acclimating, especially if they're coming from a very different tank. At least temp should match, but salinity would be something as well. If it came from a LFS, the SG could be way off. I always match temp, then often add a bit of my tank water to the container. Not as much as I would with fish, but I spend a bit of time.
I have added colonies before without this, and they've been ok, but try to acclimate as best you can to get the best chance of survival.