Hi @GoofyGarra
I have had my experience with Java Moss but I just recently had the growth I was looking for and here are the conditions I have to help it thrive: moderate to low light, 10 hours of light a day, it being shoved into the substrate not on rocks or wood, have my temperature at a steady 76 degrees, the ph at around 6.6.
IMPORTANT: It took several weeks to see noticeable growth within the moss!!! Be patient!!
These are the conditions of my tank with my Java Moss. I hope this helps!