Now that I'm at work I can see the pictures a bit more clearly. I think I've got two of my glass walls completely covered in it. It doesn't protrude does it?

In my case it almost seems like a velvet covering. My snails move on to it, but I've nver bothered to clean it off... much to the annoyance of Karin who insists that I'm losing good quality reflective light.

The bright green stuff that you have on your power head is what I call "green cyano"... not sure what it is exactly, but it shares a lot of the same characteristics of the common red cyano.