agentho

Hi folks,
I just picked up some Water Sprite at a LFS yesterday. It's the first time that I've seen plants that weren't near death at a fish store. Anyway, I was excited because it looked like a big bunch and it was rooted. After I brought it home, I realized that it will soon crowd the rest of my stem plants. I had also heard that Water Sprite grows better as a floating anyway. I was thinking of dividing it and having some float and leaving some in the substrate.

Problem is this, there's a pretty big root ball.
Should I be dividing the root ball as well and let everything float
OR
should I cut the roots off and just leaving the stems?