Merman’s shaving brush, Penicillus pyriformis, is a common, shallow water marine algae found throughout the Caribbean and Tropical Atlantic. As it’s name suggests, it looks like an old fashioned shaving brush. It really adds a nice touch to any kind of aquarium and it normally left alone by most fish but it can get a “hair cut” by a hungry sea urchin. This macroalgae actually helps to reduce nitrates and phosphates but also requires supplemental feed with trace elements. Most customers plant them in their sand bed or you can also add them to your refugium.