The Seachem MatrixCarbon Aquarium Filter Media is a one-of-a-kind activated carbon. It is designed as a spherical bead for optimal hydrodynamics and will not pack. Its high density of macroporous binding sites allows for maximum water flow and contact. MatrixCarbon has a very low ash content, as evidenced by its minimal pH impact. It does not raise the pH above 7.0 when added to distilled water. Regardless of false claims to the contrary, MatrixCarbon has the lowest detectable leachable phosphate content of all major carbon brands tested. MatrixCarbon outperforms other high-grade carbons by at least a factor of two in terms of total capacity to remove organic matter from aquariums, rate of adsorption, and duration of use.
While carbon is commonly thought to be a chemical filter, this is not entirely correct. It is, in fact, a mechanical filter, but it can only mechanically filter objects of molecular size. It works by passing through extremely small cracks and crevices known as macropores and micropores. Microporous carbons are best suited to air filtration because they remove primarily metals and smaller ions (such as trace minerals), whereas macroporous carbons are best suited to water filtration because they remove primarily larger organic molecules (such as nitrogenous waste).
The ingredients used to create carbon determine whether it is macro- or microporous. Carbons derived from coconut shell and other organic materials are microporous, whereas carbons derived from bituminous coal are macroporous. MatrixCarbon is a macroporous carbon derived from bituminous coal. It is the market's only spherical carbon, allowing for maximum water flow. It is large enough to allow full water penetration but not small enough to escape filter bags. Phosphate is found in all carbons. That phosphate, however, DOES NOT come from washing the carbon with phosphoric acid. Sulfuric acid is used to clean the majority of carbons. The phosphate is found in the carbon source's ash. The primary goal of acid washing is to remove ash. Because of the hydrodynamic properties of MatrixCarbon, more ash is washed from our carbon than any other. As a result, it has the lowest leachable phosphate content on the market.
