I think I'm the only one with tank where java moss is miserable, it's either going brown and dying or grow really slow, I do have floating wisteria, cryptocoryne green and christmass moss, and those plants are doing ok, only java moss struggle, my temp is 74-75F and no Co2, it's a shrimp tank only,what to do?
For me, java moss grows the best the more I neglect it. I would make sure its loose, not balled up or the middle dies off, and stick it in a place that gets some water movement. Forget about it for several weeks. You should see new growth eventually. If you have enough, break it up and place it in several spots in your aquarium. You may find it's happier in some places than others.
I had same problem w/JM while other plants did fine. I have noticed as many others have that JM gets most of its nutrients from the water column. The original plants appear to die and leaves turn black but new plants start to develop from these blackened leaves. I take these new plants and put in gravel. These new plants then grow fine.