The Lucky Bamboo won't grow fully submersed. You'll want to only submerse the very bottom and the roots, leave the stem and leaves sticking out of the tank. It will eventually rot away if fully submersed.
polish, the top of the lucky bamboo like the leaves and stuff stick out of the tank, but I didn't know it would grow a completely new one. I put it in and it was only 1.
The new one just popped up.
Oh ok, I see. I think you can cut those small guys off and stick just the bottom of it in the water. Do a little Google searching on how to trim it off and keep it alive. It's not hard at all but I am not sure how big it needs to be. I trimmed one a while back but it was larger than that however it started to grow roots in a couple weeks.