I recently bought a plant at a LFS labeled merely "cryptocoryne XL". It has long strap-like leaves that are sometimes wavy. The Xl referred to the mass- I divided it into at least 15 plants. One went in my 20L under 48 watts of T5. That one has turned maroon, is beautifully wavy, and has more than tripled in mass, but not reached the top of the water. The others went in a regular 20 gallon with the same light. They are green, and have grown up and across the top of the tank, totally blocking the light. Now what? It doesn't seem right to whack the leaves in half to let in light. Yet I think if they could get the light, they wouldn't be reaching so high, if that makes sense. What is this plant, and how should it behave? What makes them happy?