I gotta tell ya, I've been told over and over again that feather dusters are very fragile and should be handled with care. Not true!!!
I was moving a piece of rock the other day when I noticed a tugging, I stopped and looked behind it and the tail of the feather duster was pinned under it. This feather dusters tube is about 6 inches long and the feather spread is about 5 inches wide, so its a nice size one. Anyway, I thought that the rock was only sitting on it, so I lifted and it cam out easy. I looked at the rock and the whole tube was there, hanging. Ilooked in the tank and the feather duster was still there, without the tube, naked, really ugly. Within 2 days he had built a whole new tube and is doing fine. They bounce back very well.
Don't tap on the glass, the fish will think you are stupid!!