Chemiclean is an antibiotic that will only work on cyanobacteria. What you have doesn't look much like cyano to me.
Yes, before I went under a scope, some of it was red in the sand bed. Figured it couldn't hurt as I have been at my wits end. I believe the long spell of lower phosphate is starting to turn the tide. Maybe the reef flux is what is helping. All I know is the algae is going away without having to keep the lights out all the time.