Yes, Java fern absorbs ammonia. Despite being a slow-grower, this classic aquarium plant efficiently absorbs ammonia from the water.
Additionally, Java fern can also absorb nitrates, nitrites, and carbon dioxide, making it one of the best aquatic plants for maintaining the water quality in your tank.
Moreover, this aquatic plant is also a natural harborer of helpful bacteria, so when taken care of properly, this plant can help nurture an abundance of beneficial bacteria in the tank. These bacteria will absorb even more ammonia, nitrates, and nitrites from the water, keeping your tank cleaner for longer.