Anyone know what this is?

[james.c]

This stuff is tough. Doesn't come off easy, stuck hard to rock and can't blow it off with baster or power head. I've started dosing Vibrant twice a week but no luck so far after week three. This stuff is slowly covering all the rock work and if not controlled with destroy the tank. I've never encountered this stuff before. Not hair algae nor cyano, or dinos.... something else.

 

[MnFish1]

This stuff is tough. Doesn't come off easy, stuck hard to rock and can't blow it off with baster or power head. I've started dosing Vibrant twice a week but no luck so far after week three. This stuff is slowly covering all the rock work and if not controlled with destroy the tank. I've never encountered this stuff before. Not hair algae nor cyano, or dinos.... something else.

Assume you're talking about the red patch? Do you think its coralline? I assume you've tried brushing it off (like with a toothbrush) - does that work? Is it 'soft' or 'hard'

 

[james.c]

This stuff is tough. Doesn't come off easy, stuck hard to rock and can't blow it off with baster or power head. I've started dosing Vibrant twice a week but no luck so far after week three. This stuff is slowly covering all the rock work and if not controlled with destroy the tank. I've never encountered this stuff before. Not hair algae nor cyano, or dinos.... something else.

Have added a few more pics. Brushing with toothbrush did nothing. Have killed it with Hydrogen Peroxide but stuff is really prolific. Feels like velvet or felt to the touch.