Many contaminants found in water can be toxic to saltwater and freshwater fish, reptiles, amphibians, and turtles, and should be removed from the water used in fish tanks or ponds.

Removing chloramines can be more difficult than removing chlorine. The activated carbon provides an active surface for chloramine reactions to take place, and carbons with catalytic functionality tend to perform well in this application. Catalytic functionality carbons provide faster reaction rates than conventional carbons.

Activated carbon is also commonly utilized in aquarium and pond filters to reduce organic content in the water. Organic compounds can range from weakly (acetone, methylene chloride for example) to strongly adsorbing (trichloroethylene, tetrachloroethylene, toluene, xylenes, naphthalene, phenol, etc.) species.

Granular activated carbon

Granular activated carbon is a proven and economical technology which is effective in reducing Chemical Oxygen Demand (COD), Adsorbable Organic Halogens (AOX), pesticides, solvents, organic compounds and other toxic substances. The amount of GAC to be installed is related to the flow to be treated, but equally to the organic load and the treatment objective.