Chemical Filtration Chemical Filtration Chemical filtration is the filtration of water through some type of absorbent material such as carbon and zeolite. Chemical filtration is the least important of the three and should not be relied on to heavily. Many aquariums run without carbon and zeolite simply because water changes are performed frequently and there is generally a low stock of fish in the aquarium.
Carbon is used widely in the aquarium hobby to rid the aquarium of smells and discoloration.
It can remove a wide variety of chemicals from copper to chlorine. Carbon is generally included in most filtration systems and should be frequently changed. When to change carbon is dependent on the amount of fish in the aquarium. As a general rule in the aquarium hobby most aquariums need to have the carbon changed once a month. Zeolite has the ability to remove ammonia, because zeolite attracts positive charged chemicals.