2 questions: driftwood fungus and java moss

[osromatra]

First, I had some white fungus grow on my driftwood when I first started to cycle the tank. Once the mollies were in, they ate it up. It was gone for about a week.

Well, the other day I was adjusting some decor and noticed patches of more fungal looking stuff, in the same spot as the white fungus had been, only now it's thicker and black or gray. It also looks "chunkier" and occasionally I will see a chunk floating around (usually after a water change). Should I take the wood out and blast the stuff off? I've left it alone at first, it doesn't seem to be spreading and my parameters are all good. I had a platy die mysteriously though, so I worry it's poisoning the water. I tried getting a good photo but can't- it's so dark, it really doesn't stand out enough in my photos.

Second, I really want to add java moss to my driftwood. We have anubias, amazon swords, I think moneywort and some type of wisteria, all growing well. Should I, and if so, how, do you get java moss to take off? I'd have to special order it, no one local has any.