Algae ID question

[gmdcdvm]

Hello Everyone,
Just trying to figure out what this is. On the walls of my tank I get a reddish brown algae that seems almost like a coating of dust. It is very easy to scrape off with no effort. When I scrape it off you can see if disperse in the water as if I just dropped a bunch of dust into it and it does not grow anywhere else. Just wondering since all of the other algae that have grown on the walls before were either hard to remove or had a different appearance.
I can take a picture, but it just looks like a coating on the glass.

Gerry

 

[lapin]

It might be cyano which is a bacteria.
I also might be a film algae.
Film usually grows on glass where cyano does not.