Hi Lance,
I have a fox face and sailfin tang that nibble on some of the green stuff - but not the fuzzy patches in the picture. I would have to tear the whole tank apart to remove the rocks that are affected - I wish I could borrow your fish!
I've been reading on the DFWMAS forum tonight about raising the magnesium to 1600 to help. Wonder if getting a lawnmower blenny would help too? I've got a phosphate sponge in the sump just in case even though my phosphate tests zero. I use RO/DI water to mix salt water and to top off. My TDS meter reads 1. Not sure where I picked up this algae....Candace