Fertilizing Your 'Bamboo' In Water
I have a Lucky bamboo that was doing ok when given to me, but not really thriving. I read a little before doing anything and then started doing my own thing. I like how it looks and wanted to keep it in the water. It is a nice clump of "bamboo" in water with black rocks. I thought about putting it in soil but didn't want to risk it. I began dumping out it's water monthly, always using distilled water to fill it up, and giving it some kelp water. Kelp is a great fertilizer for almost every plant. I'm not sure how readily available it is in other places but I use it as an organic alternative to chemical/man made fertilizers with all my plants, including my orchids and produce.
The concern with plants in water when using chemical fertilizers is that too much chemical junk is left behind in the container. This can poison your plant. If you can't find dried kelp try changing all the water bi-monthly when you use fertilizer. Always use distilled water, I can not stress this enough. I also stop using fertilizer come this time of year. You want to give them all that good stuff when they are growing and will use it. You should still do water changes during the winter though.
My plant has done great, and looks good too! I recently decided that the plant could use some more root room so I removed a good portion of the rocks, when that space becomes filled up I will put it in a new container. (Planting it in soil.) I think they look nice in glass and can do fine for years if taken care of. Why not keep it that way for as long as you can? It seems most people are not as dedicated to their plants, but it's really quite easy to take care of.
I think the two other keys to keeping the lucky bamboo happy are temperature and light. I make sure my plant is nice and cozy with soft sun light and in a room that is kept warm year round. I also rotate my plant whenever I remember to or feel like it.
Your lucky bamboo can be in water and look nice, but when it's time it's time and it should be planted. I wish you luck with your plants.