I bought a bamboo plant that you keep in a vase of water, whats the best way to take care of it for growth?

Question

do i just keep it in water, add plant food?

Answer 1

as y ou said, keep it in water, forget the plant food and keep in out of the direct sun light.  good luck and be patient.  

Answer 2

Known for centuries as Lucky Bamboo, the plant is not a bamboo at all (botanical name: Dracaena) but a resilient member of the lily family that grows in the dark, tropical rain-forests of Southeast Asia and Africa.

Not hard to take care of change water once a week, Miracle-gro makes liquid plant food that is the easiest way to fertilize the bamboo. Just a couple of drops once a month will be enough. But not necessary. They live in low light very well. I have mine in a bathroom with no window.

Here is my favorite site for bamboo, it has all the information you will need.