Ok, I can't seem to pull any threads on this.

This morning when I got up one of my sps corals had a dusting of white powder in the basin of the coral. Last night there were white flag like things swinging in the current. When I saw the dusting this morning I turkey basted it.... then thought that may not have been a smart move. None of the other corals seem to have this, here is a picture I took this morning but it's not very clear.