I've had this lucky bamboo in my tank for over a year. It's in hanging baskets near the top and near a window so it gets indirect daylight all day. It seems very healthy and the leaves look great but the stems don't seem to be much if any taller then when i got them. Is there any cause for concern or pruning or anything? Is there some reason the stems don't seem to grow any taller? Any info is appreciated. Novice here...