Fluval zeo-carb is a water filtration medium used in home aquariums. It is a mixture of high-grade activated carbon, which helps filter waste and other impurities, and zeolite, an ammonia remover.
Excess ammonia, released into the water in your fish's excrement, can be toxic and alter the pH balance of your aquarium. Zeolite binds with ammonia and other nitrogenous compounds (e.g., nitrite, nitrate), thus helping maintain the health of your aquarium. Fluval Zeo-Carb's high-grade activated carbon serves as a general water purifier. Both organic (e.g., copper, chlorine) and inorganic (e.g., antibiotics, dyes) impurities bind to the porous surface of the carbon, which has the added benefit of keeping your aquarium's water free of discolouration.
Zeolite can be recharged by placing it in a strong salt water solution. However, the high-grade activated carbon must be replaced every four to six weeks to avoid impurities seeping back into the water from the carbon. With Fluval Zeo-Carb being a mixture of the two, zeolite is unnecessarily discarded whenever the carbon needs replacing. As such, it may be less wasteful and more cost-effective to purchase the two separately.
Fluval zeo-carb can only be used in freshwater solutions. As some zeolites have a strong affinity for calcium, they may not be as effective at removing ammonia in hard water. Some corals are highly sensitive to changes in water chemistry and may react negatively to the introduction of zeolite to a filtration system.