Attaching to glass, gravel, rocks, wood, even other plants that moss sounds like really "easy" or "difficult" stuff, depending on whether you're trying to grow it or get rid of it.
![Razz :P](./images/smilies/icon_razz.gif)
On another topic, to follow up on that wafer it is still not gone yet. It's sitting right in the shrimps' hangout, but they don't seem to be showing interest in it anymore. If it weren't such a small piece I'd want to take it back out to prevent the pollution, but it would probably be more bother than it's worth. I might try again in a week or so, after I've tried a vegetable or two.
In other news my wife and I are thinking about picking up a couple balloon mollies - a black one and a white one. We picked the colors because my wife would like a varied tank and we only have silver, red, blue, and orange so far, but it may be particularly fitting for MLK day - though I wonder if anyone would find that offensive? We might end up putting our "MLK day fish haul" on youtube if we feel adventuresome enough, haha.
EDIT: For better or worse the black balloon molly we saw yesterday afternoon had already been sold. A couple healthy-looking white ones were still available, but we wanted to get both at the same time so no new fish today. Also no potentially controversial youtube video, haha.