#cyanobacteria

So, i was going to introduce my tank and ideas here, since i'm new, but there is something bothering me at my tank so i'm going for this first. The reason about this post is to see if anyone have experinced something like this before or know what kind of organism is that... Basically several...

Is this cyanobacteria I did two back to back treatments of cyanobacteria no improvement any suggestions?

I’m new to saltwater and bought a reef aquarium that’s a few years old. There is a horrible reddish stuff growing over everything which I’m guessing is Cyanobacteria. A worker at my LFS said it was probably due to the black sand. I really hate the look of the black sand in there anyway and am...