I scraped off lots of the pre-coralline stuff on my front glass tonight - the red and green stuff that won't come up with a scraper. Maybe its not coralline, but I'm pretty sure it is. This is the thing layer of stuff,before it starts to build up (its thin cause I keep scraping it with the magnetic thing).
I used a razor blade - a high-end one for cleaning glass (no scratches, btw).
The stuff came off in rolls, kind of like if you were shaving chocolate.
So, when I was done, I had all these little rolled up "tubes" of coralline all along the front of the tank.
Well, I think my parrotfish and yellow tang were in heaven - it took them about 2 minutes to gobble it all down. I've never seen them eat anything so ferociously!