A Protein Skimmer works by producing thousands of tiny micro bubbles by mixing water and air. Popular methods of producing bubbles are needle wheel, venturi, counter current and air stone. A Protein Skimmer requires a certain amount of surface tension to function and will not work in freshwater aquariums, only saltwater. Proteins and different wastes attach to the micro bubbles and are forced to the top of the skimmer’s chamber. As they reach the surface, the bubbles pop, releasing the waste into the neck of the skimmer. Over time, the skimmer produces a thick foam of bubbles that rise up the neck and into the collection cup.

One advantage to a Protein Skimmer over conventional filtration is any waste collected is immediately removed from the aquarium, and no longer has an impact on the biological and mechanical filtration. In a sponge filter, waste becomes trapped and is broken down by bacteria. This process is not immediate and while the waste is being broken down, your aquarium’s water is still running through it.
When selecting a Protein Skimmer consider whether it will be used In-Sump or will Hang on the Back of the aquarium. Hang on the back skimmers are typically suitable for aquariums up to 55 gallons, whereas some in-sump skimmers are made for aquariums over 1000 gallons! When researching your skimmer, a general rule of thumb is to take the manufactures suggested rating and divide by two. For example, a skimmer rated for 220 gallons, would be suited for an aquarium up to 110 gallons. Most aquarists will agree it is better to have more filtration than less, so take into consideration the number of fish you plan to keep and the ideal water quality needed by any corals in the system. Please note, some aquarists believe that you can remove too many nutrients from the water by overskimming, these hobbyists have their protein skimmers on a timer to run during specific times of the day or do not use a Protein Skimmer at all.
Purchase the best Protein Skimmer your budget can afford. Typically a Protein Skimmer under $100 will be difficult to adjust, is likely to break and will provide minimal filtration power. It is better to spend more money once and get a good Protein Skimmer, rather than buying a poor skimmer and then having to upgrade later.
A Protein Skimmer is not necessary for a saltwater aquarium, but many hobbyists agree that it makes the hobby much easier. This subject is often a topic of intense debate and whether you choose to use a Protein Skimmer or another method of filtration is your choice. The purpose of filtration is to maintain a particular level of water quality. However, the level of water quality you choose to keep and the method of filtration used is simply personal preference.
For most beginner hobbyists wanting to maintain a small aquarium with just a few fish, a Protein Skimmer is not necessary and they can use a standard Hang on Back Filter. Yet, most beginners have a tendency to overfeed their aquariums and make other newbie mistakes, which often cause nitrates to rise and algae to grow. Having a filter in place that can compensate for those mistakes can make the hobby more enjoyable.