The pieces I added from Brandon are two stalks of Frog Spawn, 3-4 pieces of Acropora, about 20 brown/green palys and a half dozen mushrooms on rock.
I wouldn't think any of that would cause it, but this my first experience with Acropora. I don't know if it is normal, but the Acro's polyps have been open for most of the day and I just put them in last night. That is a good sign I hope. They did slime up a bit though when I glued them to some pucks.