purple algae ID

[dcv82]

Anyone have any idea of what type of algae this is and what solutions there are for controlling it besides the phosphate filter route that I have in place now. I also have a purple, sailfin and naso tang that don't seem to take a whole lot of interest in it. It is purple/deep maroon red in color, grows in a spider web fashion and grows tight to the rocks like turf and is only sticking out about a quarter of an inch or so.

http://reefcentral.com/gallery/data/500/94089purple_algae2.bmp

Thanks