is this normal... i got my first birds nest today and it looked good during the day but this evening at lights out some of them retracted...is this normal?
It might take a few days or so for the polyps to come out. At night time the polyp extension should be a little better than the daylight, since they usually feed then.
But again, I wouldnt give it much thought, it was just added. Give it some time to get used to your tank