Bigger is better when it comes to a protein skimmer, right? Not necessarily. Using a high capacity protein skimmer on a smaller tank can be problematic. Why? Well, using an oversized skimmer will result in an inconsistent performance.


Let me explain. To perform optimally a skimmer should be working all the time. An oversized skimmer will tend to skim well for a few days then slow down once all of the organics have been skimmed out. Once the organics build up again the skimmer will spring back into action, and thus perform inconsistently.


How do you know whether you have the right size skimmer for the tank? I was always under the assumption that sizing should be based on total gallons in a system so I figured a frag tank plumbed into the display would count. Is this misguided thinking? According to one large manufacturer, they base skimmer size on the display volume of a tank system since that is where the main bio load is concentrated. The number of fish producing poop also factors into the equation.


Not all manufacturers agree on how to size a skimmer so it is important to discuss sizing options directly with the manufacturer or with someone on the retail side who sells the product and has experience using it.


Skimmer Foam


So what makes me qualified to write this article? Well, I do have some first hand experience on the topic. The total system volume for my reef tank is 250 gallons and the skimmer I had initially was rated for heavily stocked aquariums up to 375 gallons. Some days it would skim and other days it would not, yielding less skimmate then expected.


I ended up replacing that skimmer with another one rated for smaller tanks and, lo and behold, it produced more skimmate on a more consistent basis. Lesson learned.


Skimmer Foam



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If you are looking for additional insights and information, please explore my many other reef tank and SPS related articles as well as my book, A ReefBum’s Guide To Keeping an SPS Reef Tank: A Blueprint For Success. And you can see all of my reef tank videos online now as well as my Live HD Webcam.


Happy reef keeping!