Q.small brown spots and yellow-brown leaf tips
My indoor -in water- bamboo plant has suddenly developed small brown spots on the leaves and some of the leaves are yellow to brownish. What should I do? The plant is about 3yrs old and was a gift. I would like to keep it healthy.
Thank you for your help.

Here is a link with care information.
It could be suffering from fungus and a treatment with Neem Oil may help.
https://www.gardeningknowhow.com/houseplants/lucky-bamboo/growing-lucky-bamboo-indoor.htm
https://www.gardeningknowhow.com/plant-problems/pests/pesticides/neem-oil-uses.htm