Protein skimmers are arguably the single most important piece of filtration equipment on our marine and reef aquariums, and in general they are rather efficient at removing dissolved organics and easy to setup and maintain. Unfortunately, they do have an Achilles heel, so to speak. Protein skimmers are very reliant on air and water flow through their pumps in order to perform properly. And because even the slightest things can alter the volume of air and/or water the pump draws, a protein skimmer can work very poorly if not placed at the manufacturer’s suggested water depth and if it’s not cleaned and maintained regularly. So, to get the most out of your protein skimmer, monitor it daily and be sure to take it offline every few months for a thorough cleaning and inspection.