Mine grows fine, except it's funny how it totally changed from the plant that I bought it (short wide leaves) to the way it looks now - long narrow leaves.
I actually replanted it last weekend because it had reached the top of my 20L. I took it out with its now massive root system - I cut off the roots and replanted them, I cut out the middle portion and threw it out, and took the top 3-4 inches and stuck them back in the sand. I'm sure they will grow roots in no time. This is one of the two plants in my tank that is doing really well.