Kim on Protein Skimmers
Jason Kim Walks the Aquarist through the Basics of Skimming
President of San Diego-based AquaC, Inc, one of the most respected protein skimmer manufacturers in the United States, explains how they work and which to buy.
As Jason Kim, President of San Diego-based AquaC, Inc, says, “All protein skimmers available to the home aquarist operate on the same basic principle.” Inside a protein skimmer, bubbles, laden with waste (proteins and other molecules), rise and form a thick foam which is then skimmed off. Unlike other filtration devices, protein skimmers allow the waste to then be completely exported from the system. “Other than a water change,” says Kim, “there is no better method of keeping a marine aquarium clean.”
There are very few situations in which a saltwater aquarist would not want to use a protein skimmer. Having said that, how does the aquarist choose from a plethora of skimmers and skimmer technologies? How does the aquarist separate the wheat from the chaff—or, as the case may be, the water from the skimmate?
“There are several general rules of thumb that can be used to identify a good skimmer from a bad one,” says Kim. The skimmer that produces more small bubbles is better than a skimmer that produces fewer large bubbles. More bubbles equals more skimming and smaller bubbles have a higher surface area to volume ratio. In addition to number of bubbles and bubble size, contact time is also important. Longer contact time is better—more time for the bubbles to interact with the waste in the water.
While there are many other considerations, the aforementioned ones have the most impact on a skimmer's overall efficiency. Other points to consider include pragmatic concerns such as ease of maintenance and energy efficiency. “Some skimmers are terribly difficult to clean or maintain,” says Kim, “and others are such energy hogs that they end up costing more in the long run.”
As anyone who has shopped for a skimmer knows, most look essentially the same. They are generally cylindrical in shape and have a similar body design. The main difference is in what you may not see at first glance—the method of air injection.
- Air-driven
- Venturi-driven
- Downdraft
- Beckett
- Spray Injection
- Needle-wheel driven
So which technology is the best? “All of these different designs have their merits,” Kim responds. “Only a fool would claim that one is definitively better than another.” While that is nice to hear from the president of one of the most respected protein skimmer manufacturers, it doesn’t help the hobbyist make a decision on which skimmer to buy. Considering the different criteria—and cost is admittedly a big consideration for most—Kim recommends that the beginning hobbyist start by looking at a venturi driven, spray injection or needle-wheel skimmer. “Lucky for hobbyists,” Kim adds, “the market for protein skimmers is simply too competitive to manufacture junk these days.” In other words, most are going to do the job.
Many introductory level skimmers are venturi-driven and best for tanks under 50 gallons. “Performance is so-so,” Kim says, “but they are inexpensive ($100 or less) and widely distributed, which makes them appealing.” Needle-wheel skimmers can be grouped with venturi skimmers, as they rely on a venturi valve. The difference is that the air moves through a modified pump impeller designed to shred the air bubbles into a fine mist. Since smaller bubbles (and more of them) are best, it could be said that a needle-wheel skimmer is the best choice for the beginning hobbyist on a budget.
“If I were going to offer advice to a beginner,” Kim concludes, “I would say that it is most important to buy a product from an established company that has a track record of producing quality products and good customer service.”
In the next article in the protein skimmer series, Kim will provide additional insights regarding the individual technologies.
Kim on Protein Skimmers - Jason Kim Walks the Aquarist through the Basics of Skimming (Part 1)
Venturi and Needle Wheel Skimmers - Two of the Most Popular Skimming Technologies Explained (Part 2)
Spray Injection Protein Skimmers - AquaC's Patent Process Relies on Brute Force (Part 3)
See all of Ret's Marine Aquarium articles here.
