The chemical filtration is not in the bio-wheel itself. The Bio-wheel is a separate media that provides the home for the biological filter, keeping it oxygenated and out of the box. Also, it makes for easy cycling if you wish to move one bio-wheel to a cycling tank, for instance. The chemical filtration is inside the box. It is just some filter foam attached to a black plastic frame with some activated carbon inside. You can take the foam off, remove the carbon and then rubber band on the mechanical filtration of your choice from polyester batting to filter floss to sponges.NFR-22467-A said:are the chemical filters removable in the penguin biowheels?