I guess I am as wrong as you Randy, because I've experienced the same thing. I run a healthy Xenia fuge, and the only time I see growth in the Chaeto is when I've create a large surplus in nutrients by either over feeding or large decay in the tank. I am currently skimmerless and my chaeto grew a little when I first turned the skimmer off. Now that the Xenia has grown to fill the surplus of nutrients created, the chaeto growth has stalled. Also when I remove it I see no difference in amount of algae in the DT. Now when I do Xenia pruning I see an almost immediate algae bloom on my glass for about a week. Until the growth of the Xenia fills the void.