If you’re like most aquarium hobbyists, you probably have sump below your reef tank that houses an oversized protein skimmer and possibly a populated refugium. The refugium is full of macroalgae that requires some form of illumination to grow. This lighting serves its purpose well, and the macroalgae is growing beautifully, but that’s not the only thing growing unfortunately. The excess light can spill into the skimmer section of your sump, often causing some form of algae to grow in the skimmer itself. This isn’t a problem, typically, but it can certainly cause issues with the protein skimmer’s performance if routine maintenance and cleaning aren’t performed. Completely breaking down the skimmer every couple of months and giving it a good warm water soak with a little vinegar should remove any excess algae and calcium deposits, and should keep your skimmer running in tip top shape.