Basically, the smaller the air bubbles the larger the surface area is, which means that more waste can be removed from the system. Furthermore, small air bubbles will take longer to travel to the surface and this will allow more time for it to collect the waste material. Therefore back to the question whereby, does freshwater tank benefit from having protein skimmer? The answer is definitely NO because the water itself does not create that kind of surface tension to allow formation of these fine air bubbles.
Learn the tricks to having successful marine tank:
» Right Way to Set Up your Saltwater Tank
» Populating Marine Coral Tank
» Saltwater Fish Disease and Treatment