Final answer:
The best way to eliminate ammonia in aquariums besides water changes is through biological filtration, which converts ammonia into less toxic nitrates using beneficial bacteria, and by introducing aquatic plants that absorb ammonia and nitrates.
Step-by-step explanation:
The best and safest way to eliminate ammonia in aquariums, besides water changes, is through the establishment of a biological filtration system, which uses natural processes to convert harmful ammonia into less toxic substances. Ammonia is a byproduct of fish waste and decaying organic matter and its buildup can be harmful to fish. In a process called the nitrogen cycle, beneficial bacteria such as Nitrosomonas convert ammonia into nitrites, and another bacteria, Nitrobacter, then converts nitrites into nitrates, which are less toxic and can be absorbed by plants or removed through regular, less frequent water changes.
To facilitate this process, an aquarist can add a biological filtration media to their aquarium filter, where beneficial bacteria can grow and thrive. Additionally, introducing live aquatic plants can help absorb some of the ammonia and nitrates. Regular monitoring of ammonia levels is essential to ensure the health of the aquarium inhabitants.