Well, I went to visit my parents last week in Ohio and came home on Sunday night to a tank FILLED with Dictyota. I'm sort of out on a limb with my feelings of this stuff. It doesn't seem to effect corals, it might try to shade them out, but it doesn't sting, as of yet. It will grow on exposed acro skeletons though Just wanted to show people what Dictyota can do. If you see it....GET IT OUT NOW!!!!