If your lucky bamboo is in soil, water when the top 50% of soil is dry. Water thoroughly until it flows out of the drainage hole and discard any excess water. If the plant sits in soggy soil the roots are not able to breathe which can lead to root rot.
If your bamboo is in water, be sure to keep the water clean. Change the water weekly or as needed to keep the water clean and discourage fungal and bacterial growth.
Yellowing and browning on the leaves can be caused by the tap water used to water your plant. Normal tap water can have a lot of things like added minerals and fluoride in it that can affect sensitive plants like this. If possible, use distilled or rainwater. If this isn’t possible you can leave some tap water out overnight to evaporate some of the chemicals. Even if you’re using filtered water, check with the brand’s manufacturer to see if they filter out fluoride since most do not.
Too much bright light can cause the leaves to appear washed out or pale. On the other hand, too little light can cause the leaves to turn yellow and drop. Your lucky bamboo prefers indirect bright light. Bright indirect light can be found in places close to an east-facing window or a few feet back from an unobstructed southern or western window. If the southern or western window has something like a sheer curtain, or natural shade from a tree or building outside, the plant can be placed a little closer.
Lucky bamboo requires very little fertilizer. Too much can burn the roots and cause the plant to yellow. Fertilize only once in the early spring.
Lucky bamboo is very forgiving, thriving in temperatures between 65-95° F. However, rapid shifts in temperature can cause the plant to go into shock, so try to keep your plant away from any drafty windows or air vents.
If there is new growth on your plant and the yellowing leaves are older, particularly at the bottom of the plant, this yellowing is natural. Your plant sheds its old leaves and sends energy to new growth. You can simply trim any old leaves off to help your plant focus its energy on new and healthy growth.