Add a few drops of fert macros to the tank. Mosses respond very well to this.
I've managed to get some really dark green growth out of browned moss this way.
Thanks, I did this. I also transferred a bunch of java moss out of another tank, so now there are 4 mossy divided sections. I need to get them attached to some SS mesh or something, so that I can remove the glass dividers and allow some flow in there.