What is Protein Skimming?
Published November 25, 2008
- RSS/XML Feed 
By Robert Lashlee
Protein skimming is a water purification method used with many saltwater aquariums. Skimming removes dissolved and particulate organic matter from your aquarium’s water and provides increased aeration.
Why Don’t You Want Excess Organic Matter in Your Water?
Organic compounds are those that contain both carbon and hydrogen (and can also contain other additional atoms). Frequently these compounds contain nitrogen or phosphorous and if these compounds are left in your water, they can be broken down to form nitrates or phosphates. Additionally, metals can bind to organic materials making them more toxic and/or soluble. For some metals, this is not harmful, but for others (like copper) if the concentration gets too high, your aquarium inhabitants will suffer. Finally, toxins that are released by some species are organic compounds.
How is Protein Skimming Different from Normal Filtering?
Protein skimming is a form of mechanical filtration, but it is different from standard filtration methods in several ways:
- The materials a skimmer removes are physically removed from contact with the water. In traditional mechanical filters, the uneaten food, waste, etc. are trapped, but are still left in contact with the water. With a protein skimmer, the organic materials are moved to a separate holding container where they can be removed by the aquarist.
- Protein skimmers remove particles that are molecular-sized. Typical mechanical filters remove particulates that are millimeter-sized. Skimmers operate on a much smaller level.
How Does Protein Skimming Work?
Skimmers generally consist of a tube with a collection cup on top. Tiny bubbles move up and down this tube (tiny bubbles are used because they have a large surface to volume ratio). As they move, organic materials suspended in the water column adhere to the surfaces of the bubbles. At the top of the tube, the bubbles come together to form a foam. This foam is then forced up the tube and is dumped into the collection cup at the top. In this way, the water that leaves the protein skimmer has much of its organic materials stripped. The organic materials in the collection cup form a waste called effluent and a brine solution is also collected in the cup (you need to periodically check your salinity because skimming does remove some salts). This waste is then manually disposed of by the aquarist.
What are the Benefits of Protein Skimming?
The primary benefit is the removal of organic compounds and waste from your aquarium’s water. Dissolved compounds and very small particulate matter that cannot be removed by typical mechanical filtration are removed via protein skimming.
A secondary (but still very important) benefit is that when water enters the protein skimmer, it becomes saturated (or close to saturated) with oxygen due to the large amount of bubbles in the tube. Oxygenating the water has the obvious benefit of replicating the high-oxygen environments many of our saltwater inhabitants are used to.
Who Should Use Protein Skimmers?
Many people choose not to use skimmers and their tanks are just fine, but as a general rule, you will want to use one if you have a reef tank or a tank with invertebrates. If you have a FOWLR (fish only with live rock) or a marine tank, then the need for a protein skimmer is greatly reduced. It certainly will not harm anything (other than the added cost to your wallet) to have one with a FOWLR setup. In fact, it can be useful in removing the thin film that can form on the surface and it will increase the oxygen concentration of your water which your fish will appreciate.
Conclusion
Protein skimming can be a very effective way to remove dissolve or particulate organic materials from your saltwater aquarium. There are many different styles to choose from, but they all basically do the same thing. Refer to the Further Reading section for more information about each specific type of skimmer.
Further Reading
Read Related Saltwater Aquarium Articles
- Saltwater versus Freshwater Aquariums
- Learn the arguments for choosing to set-up either a freshwater or saltwater aquarium.
- Saltwater Aquariums
- A brief introduction to saltwater aquariums. Different categories. Pros and cons.
- Reef Aquariums
- An overview of the reef aquarium along with a short history. Online reef references.
- Setting Up A Saltwater Tank System
- What to Consider before Starting. Designing Your Salt-Water System.
- Saltwater Aquarium Filtration
- Filtration systems to use. Pros and cons of different systems.
- Saltwater Aquarium Lighting and Heating
- Kind of lights you need. Type of heating equipment to use.
- How to Keep Your Saltwater Aquarium from Overheating
- Learn how to keep your saltwater aquarium from overheating.
- Saltwater and Reef Tank Cycling
- Tips on cycling your fishtank.
- Getting The Tank Ready
- Creating an ecosystem. Running the tank system.
- How to Cure Your Live Rock Before Placing it in Your Aquarium
- Learn how to properly cure live rock before placing it in your tank.
- Creating an Aquascape and Choosing Fish
- Creating an aquascape. Deciding on livestock for your tank.
- Stocking Salt Water Reef Tanks
- Learn how to select the right quantity and combination of fish for your saltwater aquarium.
- What Are Good Saltwater Fish For Beginners
- What makes a saltwater fish a good candidate for beginners?
- Commonly Available Reef-Safe Fish & Invertebrates
- Learn about commonly available reef-safe fish and invertebrates that are good candidates for your reef aquarium.
- Establishing up a Clean-up Crew in Your Saltwater Aquarium
- Learn how to properly select and establish a clean-up crew in a saltwater or reef aquarium.
- Saltwater Species That Should Not be Kept by Beginners (and Sometimes not Even by the Experienced)
- Learn about saltwater animals that beginners (and sometimes experts) should avoid keeping.
- Maintaining Your Saltwater Tank
- Tips for maintaining a saltwater fish tank.
- Getting Rid of Aiptasia in Your Reef Aquarium
- Learn about aiptasia in the reef aquarium and how to get rid of it.
- How to Remove a Mantis Shrimp From a Saltwater Aquarium
- Learn how to properly remove a mantis shrimp from your aquarium.
- Saltwater Fish Article Database
- Articles on dozens of saltwater fish and appropriate care.
- View All Articles
Member Tanks
new tank set up
(old tank 55gallon) Updated jan 17 2009. added more rock and corals. Plus growth is insane since changing CF bulbs.
200x70x70 cm
Volume: 1000 L (nominal)
Filtration: 260 kg live rock from Lombok/Bali (Indonesia); Sump 120x50x50 cm (300 L), half of which is used as freshwater deposit for refilling; skimmer Aquamedic 5000 Shorty 2; 180 L macro-algae refugium.
Circulation: About 28000 L/h of circulation: 2 main water pumps Eheim 1060 (2280 L/h); 2 internal circulation pumps located in the sump with specific overflow; 1 internal alternated circulation pump Tunze Stream 4000/12000 L/h in conjunction with a single-controller Tunze; 1 continuous stream 6000 L/h; 2 water falls with output distributed to skimmer and refugium.
Lighting: 2x400 W HQI´s BLV 10000 K + 2x40 W fluorescent acrobuespecial + 2x40 W acrocolor + 3x9 W Power Compact; 1x70 W HQI for the refugium.
Substrate: 60 kg CaribSea Aragamax Sugar-Sized.
Others: Refill controller/leveller Aquamedic Aquaniveau, Eheim 800 pump for freshwater refill, 180 liter macro-algae refugium.
Fauna: Fish: 8 Chromis viridis, 2 Chrysiptera cyanea, 1 Chrysiptera parasema, 1 Synchiropus splendidus, 1 banana wrasse (Helichoeres chrysus), 2 Amphiprion ocellaris, 1 Amphiprion clarkii, 1 TMC clown Amphiprion ocellaris, 1 Amphiprion polymnus, 2 Gobiodon citrinus, 5 Pseudanthias squamipinnis, 2 Pseudanthias pleurotaenia, 1 Siganus unimaculatus, 1 Chelmon rostratus, 1 Pygoplites diacanthus, 1 Naso lituratus, 2 Zebrasoma flavescens, 3 Paracanthurus hepatus, 1 Acanthurus leucosternon.
Invertebrates: 50 Marshall Islands bumble bee hermit crabs, 35 ophiuroids, 2 Tridacna squamosa Marshall Islands, 1 Tridacna maxima ultra blue Marshall Islands, 1 Tridacna hippopus Marshall Islands, 1 Tridacna crocea ultra Marshall Islands, 18 Turbo snails, 25 Tiger Tail Cucumbers.
Corais: SPS: 45 assorted Acropora, 18 assorted Montipora, 9 assorted Seriatopora, 3 assorted Pocillopora, 1 Echinopora lamellosa, 1 Porites cylindrica, 2 Hydnopora rigida, 3 Stylophora pistillata pink.
LPS: 2 Euphyllia parancora green, 2 Euphyllia paradivisa green, Goniopora lobata Marshall Islands, Goniopora stokesi red, Heliofungia actiniformis, Plerogyra sinuosa.
Soft: Xenia elongata pulsing brown, Xenia umbellata pulsing white, Sinularia, Pachyclavularia sp., Palythoa sp., Ricordea, Rhodactis gigantea, 5 rocks with Actinodiscus, 2 Sarcophyton trocheliophorum, 1 Sarcophyton sp. Tonga.
Comments: I'm Portuguese and the Brazilian version of the Age of Aquariums was among the first sites where I initiated the hobby. Since then a long time has passed and nowadays I have this 1000 L reef tank. It's not easy to set up an aquarium in Portugal, the equipment is expensive and the livestock isn't beautiful, so I travel regularly to the coral propagation farms in Germany to acquire what I have today. I'd like to see my tank distinguished on the Age of Aquariums.
34 Gallon after 3 months
a few month ago :D