How do I add pics to an album in my Facebook group without having every single pic posted?

what your looking to do is not Possible Unfortunately its gonna Show a couple of Pictures in the Photo Album no matter what you do in the Group

I maybe stating this incorrectly.

Whenever I try to add a pic to the album, EVERY pic in the album gets posted all at once. I only want them posted one at a time As I Add Them to the album and not have every pic posted at the same time when I'm trying to add one pic.

Just change your privacy setting so that only you can see your posts. Then upload all the photos and then change the privacy setting back.

Why do you want to add pics to an album and not post them? Make two albums, one public and one private.