Do I Need a Protein Skimmer if I Use Carbon?

Protein skimmers and carbon have similar roles in aquariums. Each removes organic compounds from aquarium water before they can decay and produce toxic ammonia compounds. Protein skimmers do this more efficiently and reliably. In fact, most experts consider them essential for keeping marine aquariums healthy. Still, nothing prevents you from using both protein skimmers and activated carbon in a marine aquarium.

  1. Carbon

    • Aquarium carbon or activated carbon consists organic carbon processed through both heat and chemical treatments that create microscopic pores in the carbon, increasing the particles' surface area. This vastly enhances the ability of carbon to absorb organic wastes before they can break down and create toxic byproducts like ammonia and nitrite. As organic compounds accumulate, the carbon works less and less; it will eventually require removal and discarding. The exact mileage for your carbon will vary based on the quality of the carbon and how many organic compounds are in the aquarium water.

    Protein Skimmers

    • Protein skimmers remove organic waste from aquarium water. However, they do it through a physical process called foam fractionation. In foam fractionation, a protein skimmer generates tiny bubbles that rise through the water column. As they rise, organic compounds stick to the bubbles' surface tension, dragging the waste to the water's surface, where they create a foam. You'll collect and discard the foam. Several protein skimmer designs exist. The biggest difference lies in the way they generate their bubbles.

    Advantages of Protein Skimmers

    • Protein skimmers have advantages over activated carbon. They do a better job of pulling organic compounds out of the water. Many experts consider protein skimmers critical for keeping reef aquariums or even saltwater aquariums in general. Protein skimmers do not require replacement -- with the exception of some air-stone-based models that require a new air stone periodically.

    Advantages of Carbon

    • Despite the overwhelming advantages of protein skimmers, activated carbon enjoys widespread use in the aquarium hobby. Protein skimmers work poorly in freshwater, while carbon works well. Additionally, carbon costs much less than a protein skimmer, even if you factor in the cost of replacing carbon. Meanwhile, you can use both activated carbon and a protein skimmer, though most experts consider protein skimmers a requirement for keeping marine fish.