This Marineland Replacement Bio-Wheel is for the Eclipse 2, Emperor 280B and 400B Filters. As the Bio-Wheel rotates, beneficial bacteria grow and thrive on its super dense surface. As water flows, the bacteria eliminate ammonia and nitrite on contact.
Irregular rotation of the Bio-Wheel is also normal
Discoloration of pleated Bio-Wheel material is normal and desirable
A Bio-Wheel rotating at any speed is working to eliminate toxic ammonia and nitrite
Note: Marineland Bio-Wheel should not be replaced unless damaged.