What in this color

[conk]

I'm still tying to get rid of the diatom and now notice a maroon color algae on one of my rocks. What is this now?

 

[bang guy]

I would guess it is Cyanobacter. Can you siphon it out or is it attached to the rock?

 

[conk]

I can siphon it out

 

[slick]

I had a prob with t his stuff too. Try scrubbing it off with a tooth brush or something. I had to use chemi clean to kill the stuff. Once it was gone I cut down on my feeding and light duration. Has not come back yet.