Small world: I was changing my water last night and looked into my bottle of Prime to see how much I had left and I also noticed the black stuff in it. However, mine weren't floating, but were like a sediment at the bottom of the bottle.
Hey, it's in my bottle too. At the bottom.
I would have never looked if i had not seen this thread.
I assuming it's normal since you all have it too.
I bought the bottle a week ago.Still practically full.