PROTEIN SKIMMER GENERAL INFO
What Is Aquarium Protein Skimming?
Of the many possible methods for reducing levels of organic matter in aquarium water, one of the simpler and more convenient is foam fractionation, or protein skimming. 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.
Protein skimmers are made specifically to hang on the back of the tank, to sit in the sump or sit in the back of the tank. 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 Coralife Super Skimmer protein skimmer or the SeaClone protein skimmer.
We've grouped the protein skimmers by size:
We've also group 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. For the most part manufacturers are consistent--but the AquaC Remora protein skimmer, AquaC EV protein skimmer and AquaC Urchin protein skimmer are rated very conservatively. For example, the AquaC Remora is rated for tanks up to 75 gallons, but it's just as powerful as all the other skimmers on the market rated for tanks up to 150 gallons.
Different Types of Protein Skimmers
Protein skimmers are commonly listed as venturi, downdraft, needle wheel, spray induction or air-driven. These distinctions are not terribly important--all protein skimmers basically mix air and water to create foam--but here's an explanation of the differences.
- Needle Wheel protein skimmers, such as the Marineland In Sump, Aqua Medic Turboflotor, Coralife Super Skimmer, Eshopps and the Berlin Turbo replace the impeller in your protein skimmer pump with a needle wheel impeller. Air is drawn directly into the pump and the needle wheel chops the water and air into a fine mixture. The end result is that it works similarly to a Venturi design, it's just a different method of injecting the air into the water. These protein skimmers generally are supplied with a specialized pump for the application.
- Venturi protein skimmers use a venturi valve to produce a mix of water and fine bubbles. Therefore, there is nothing to replace, and adjustments may not have to be made as frequently to keep the protein skimmer working correctly. Venturi protein skimmers are also often designed to create a spinning vortex of water and air inside the protein skimmer to maximize contact time between the air and water without the necessity of a tall column. Thus a venturi protein skimmer for a given size tank will always be smaller than other protein skimmers of comparable performance. The small size means that the venturi protein skimmer can easily be hidden underneath the tank and will leave more room in the cabinet for other equipment.
- Down-Draft protein skimmers operate by using a high pressure stream of water injected downward into a column of plastic media, like bio balls, to suck air into the water stream and break the air up into tiny bubbles. We do not carry any down-draft protein skimmers.
- AquaC protein skimmers use a Spray Induction method. We're not sure what this is, but it does work extremely well.
- The CPR Bak-Pak Protein Skimmer is driven by a rejuvenation venturi powerhead. Bubble dwell time is increased by the counter-current flow in the skimmer column. The quality of the foam collected can be controlled by raising and lowering the collection cup.