why is my lucky bamboo turning yellow?

I've had this for about a year and love it. It lived in some of those plant beads that soak up the water and water the plant. It was with another stalk and as soon as i saw a problem I separated them. The yellowing plant doesn't seem to have any rotting stalk or roots and still smells like healthy earthy scent. I only use distiled drops and 2 ot 3 drops of gogo green bamboo fertilizer every three months. What do I do??????please help thanks!!!! Also the stalk isn't mushy yet. It wouldn't let me post a pic