Aquarium Protein Skimmer Overview

What Is An Aquarium Protein Skimmer?
Which Aquarium Protein Skimmer Should You Buy?
What Are the Different Types of Skimmers?

What Is An Aquarium Protein Skimmer?
Of the many possible methods for reducing levels of organic matter in marine aquarium water, one of the simpler and more convenient is foam fractionation, or protein skimming with an aquarium protein skimmer. Protein skimming is a filtration method used to remove dissolved organic compounds before they break down into toxic ammonia and nitrite compounds. In a process analogous to the production of sea foam in surf, the injection of air bubbles into the aquarium water creates a meringuelike foam when organic molecules collect at the air-water interfaces of the bubbles. This foam is captured in the collection cup and disposed of.

Foam fractionation is an important part of the successful maintenance of a marine aquarium. It is the only method available that physically removes organic pollutants from the water. All other techniques simply sequester pollution within filter media, which are then removed and replenished with fresh media. Meanwhile, pollutant molecules may be constantly exchanged between the media and the aquarium water, reducing the overall effectiveness of the filtration system. For marine aquariums, foam fractionation is a practical and simple way to control this organic pollution.

Protein skimming only works with saltwater tanks. It's primarily used by reef aquarists, but it's also the best method of mechanical filtration for saltwater fish only tanks. Visit the Filter section for an overview of how protein skimming fits into an overall filtration strategy.

In simple terms, protein skimming is the mixing of air and water to create foam that organic substances adhere to. The foam is collected in a cup that can be easily cleaned.

Which Aquarium Protein Skimmer Should I Buy?
When purchasing a protein skimmer the main considerations are the size of your tank and where you're going to put the protein skimmer. Choosing a protein skimmer that is slightly larger than necessary is better than choosing one that is slightly smaller than necessary; most reef-keeping experts agree that it is difficult to overskim an aquarium.

There are hang on protein skimmers that sit on the back of the tank and in sump protein skimmers that sit in the sump. While there are numerous hang on and in sump protein skimmers, in tank protein skimmers are relatively new.

Usually, aquarists with a sump will place their protein skimmer in their sump, and those without a sump will hang their protein skimmer on the back of the tank. If you're not certain of where you want to hook up the protein skimmer, you might consider a protein skimmer that can both be hooked up in the sump or hung on the back of the tank such as the SeaClone protein skimmer.

We've grouped the aquarium protein skimmers by size:
We've also group aquarium protein skimmers by how they are hooked up.
When buying a protein skimmer keep in mind that the tank size ratings stated by the various manufacturers are very subjective. It's very difficult to determine exactly how much protein skimming is necessary for any given tank--and there really is no correct answer.

Different Types of Protein Skimmers

In sump protein skimmers are the most popular and come in several different styles each with distinct advantages.

External Pump Skimmers, such as the Reef Octopus INT Skimmers sit in the sump with the pump outside the skimmer body. This allows for more room in the skimmer body for air and water mixing leading to superior performance as well as easy removal of the pump for cleaning.

Space Saving Protein Skimmers, such as the Reef Octopus S Skimmers and IceCap Skimmers, sit in the sump but have the pump located inside of the skimmer body. Locating the pump in the body allows the skimmer to fit in small spaces. However this design leads to a reduction in performance as well as greater difficulty when removing the pump for maintenance.

Recirculation Protein Skimmers, such as the Reef Octopus EXT Skimmers can sit inside a sump or next to a sump. External skimmers keep a recirculation pump on the outside of the skimmer body to make bubbles and require an additional feed pump to supply them with water. This design leads to the best performance of any of the skimmer designs because the bubble producing pump performs better when only recirculating. Recirculation skimmers are also popular for instances where the skimmer may need to be placed next to a sump rather than inside of the sump. The biggest disadvantages of this design is that it has the largest footprint and highest price compared to other designs.