Miniature Tube-like Feather Dusters

[volitan]

Anyone know what these tiny tube-like feather dusters are called, and what their natural enemies are? I have them growing like grass in my reef system. They are absolutely harmless, but they are overtaking the natural beauty of my live rock, and are basically leaching the calcium from the water. I know that iodine wash will kill them, but that will also kill all the critters living in the live rock, as well.

Any advice is greatly appreciated!