I only have 2 java ferns in 2 different tanks and both are doing great. The one in the 20 gal river rock tank was practically dead when I opened the plastic tube it came it. I tied it to the mopani wood with brown thread & it took off! The other java fern is in my other 20 gallon & all the leave have grown & spread with that crappy light fixture. I can't wait to see how well it does with the new light.
If mine grew any faster, I'd be saying it's moving as I look at it.

I think it is the reason the other plants are slower in growth. Java Moss is supposed to grow fastest, follower by ceratopteris and willow moss... but like everything is already backwards in my tank, I guess it's no surprise the plants do the same as the fish. (bottom feeder feeds at surface, surface feeders feed at bottom).
But do your ferns grow new leaves half dark green half light green? Or is it a sign that something's up with mine? The dark green disappears once the leaf is mature though.