Marineland Bio Wheel Assembly Replacement for the NEW Penguin 100B, Penguin 150B, Penguin 200B and 350B. Marineland Bio-Wheel should not be replaced unless damaged.
The water flow from your filter drives the Bio-Wheel. As the Bio-Wheel rotates, beneficial bacteria grow and thrive on its super dense surface. As water flows, the Bio-Wheel eliminates ammonia and nitrite on contact.