Moss balls and java moss are two seperate things. The pic above has 2 moss balls in it. They do grow, but the ball simply gets larger and they don't grow too fast. Shrimp seem to love to clean them off all the time.
yeah been wondering what those are good for, i saw them at a LFS the other day but didn't ask and forgot about them. soo what are they good for besides happy shrimp?