The use of activated carbon is sometimes a highly debated topic on most online reef forums. There are many pros and cons on the use of carbon, but I believe the general consensus is shifting towards the positive aspects of activated carbon. In order to disscouse the bad vs the good we need to know what exactly is activated carbon.

Activated carbon is carbon that has been treated with oxygen in order to open up millions of tiny pores between the carbon atoms. Carbon can be made from mineral, animal or plant-based materials such as bituminous coal, Lignite coal, various woods, coconut shells, peat and animal bones. There are three types of activated carbon they are granular, pellets and powdered. Granular is mainly used in reef tanks while pellets and powdered are used in other applications.

So now that you know what carbon is its also important to know why we use it in reef aquaria. Activated carbon offers some benefits to saltwater aquariums such as organic removal. Some people claim that they could use carbon in place of a skimmer and have a better rate of organic removal, as well as saving on extra wattage by not running a skimmer. It also removes chemicals as well as polishes the water. Soft corals are notorious for using chemical warfare in the tank, activated carbon is a good way to remove some of these chemicals.

Some of the reasons not to use activated carbons are that all carbons are organic in source. You can see from the second paragraph that carbon is all natural and therefore they are often rich in phosphates. A solution to this is that some companies will acid-wash there carbon and this prevents the carbon from leaching some phosphate. Some people will state that using activated carbon strips trace elements from there tanks water. While this is more than likely true, it shouldn't be much of a concern if you are doing weekly water changes.

I use carbon in my reef tank, personally I like the "safety net" it provides me if one of my soft corals decides to one day nuke the tank. I suggest to others to change there activated carbon once every two weeks, this way you don't give the carbon a chance to release there organics back into the tank.