Just when I thought I had my aquarium exactly the way I wanted it, I encountered a new problem: my water sprites are getting a bit out of hand. I have 14W of light in a 5.5G tank and maintain a regular fertilizer dosing schedule (Trace, NPK, Iron, Excel). The other plants are what I think are Amazon swords (the leafy ones in my avatar), and a couple of small java ferns. While the latter two are fine size-wise, the water sprites have grown very rapidly and are now above water level in places. Should I just cut them down to a more appropriate length? And what can I do to prevent such rapid growth?