The Pure Aquarium Bomb is an easy, safe and effective way to improve water quality in all freshwater aquariums. The millions of beneficial bacteria in the clear ball quickly help establish new filters with the nitrifying bacteria required to break down harmful ammonia and nitrite. Additionally, in established aquariums the bomb combats water quality emergencies, for example when the existing filter colony has been damaged by being washed in tap water or after using medication or a power cut, and finally as a boost when introducing new fish. A single dose ball for aquariums up to 200 litres.