What is activated carbon?
Activated carbon is also called activated carbon, activated carbon. Activated carbon is a form of carbon that has been processed to make it extremely porous, providing a very large surface area for adsorption or chemical reactions. Activated carbon is made from carbon, usually coal. The two most common forms are bituminous and brown coal-based. Another form that is not made from coal is based on coconut.
Granules and pellets are most commonly used in aquarium filters.
What does activated carbon do?
The use of activated carbon in a marine aquarium is considered to be a form of chemical filtration. By means of absorption, activated carbon removes gelbstoff (the compounds that give the water the yellow tint in an aquarium), some large organic molecules, medicines, chlorine, pollutants and toxins, as well as many other types of chemical elements and compounds from the water that form a protein skimmer or some other form of filtration may not be removed.
Activated carbon can also remove the trace elements and minerals that are important for your fish, invertebrates and corals. A recent study has shown that heavy use of activated charcoal in marine aquariums can cause head erosion disease on the lateral line (most commonly seen in fish in the Surgeonfish family). This can be avoided by using a trace element additive in the aquarium.
Due to the large surface area by volume, activated carbon is also a good biological filtration platform. Pelletized carbon is used in the DIY Carbon Tube Filter with excellent results. When activated carbon is placed in a filter canister, it also serves as a biological filter.
Filtration methods using activated carbon
For the carbon to be effective, water must flow over / through the carbon material. Activated carbon is used in a number of aquarium filtration systems. As mentioned earlier, activated carbon can be placed in one or more of the chambers of canister filters or in a carbon tube. Replaceable filter pads in most flow filters contain granulated carbon in the pads. Carbon can be spread in a wet / dry drop filter tray (pelletized carbon works better here). Mesh bags can also be filled with carbon and placed in a container in the water catchment area of the aquarium.
How much carbon should be used?
More is not always best, and it is recommended to use the least amount of carbon. The general consensus here is that an amount of about 3 level tablespoons of carbon per 150 liters of actual aquarium water volume should be sufficient to keep a saltwater aquarium or reef tank system colorless.
How often should carbon be changed?
Like most other absorbents, carbon can only absorb as much as it can contain. Once it has absorbed as much as possible, it will become exhausted, meaning it cannot absorb anything anymore. For this reason it must be replaced. Not all aquariums run the same, so to determine when to change the carbon, you'll have to figure this out on your own. Usually activated charcoal does not absorb anything after 4 weeks