Hi all, Ok at a loss here. Could someone please identify this red stuff think it's an algae of sorts growing on my rocks. I thought it was cynaobacteria, and bought some boyd's chemi-clean, however my substrate is clean.. Well the chemi-clean did nothing. So it can't be cynaobacteria growing. It feels like a slimy velvet when touched with my gloves. If I try brush it off with a toothbrush it comes off fairly easy in some places and very difficult to impossible in either places.. How do I remove this, I find it unsightly... Picture attached.