Self-sustaining

Self-sustaining means to be able to exist without outside help. In an ecosystem, self-sustaining means that the natural cycles that occur are able function properly without help from others. My ecosystem is not entirely self-sustaining. Without me, the fish would starve to death because there would be no source of food anymore. Also, the water would eventually evaporate, killing the fish. If there was no bubbler in the aquarium, the fish would die from lack of oxygen. If we didn't do water changes, ammonia tests, and nitrate tests, the fish would die from the pollution they created themselves. As a result of these numerous reasons, the aquarium is far from self-sustaining.