Originally Posted by Cosmo
Drs. Forster and Smith sell cartidges for your emperor 400 made out of "cell pore media" that fit into the slot where the refillable containers goe. This stuff is supposed to be some of the best bio media around and will increase your bio capacity considerably - since you won't be using this slot to add carbon in the container, it's a perfect way to increase the efficiency of the filter w/o any sacrifice. For some reason, the catalogue lists them as being for Penguin 280 and 400's, but, since there is no such thing, they actually mean the Emperors. I have one in my 280, you'd need two for the 400
:)
Jim