07-05-2013, 10:04 PM #11
Depends on your tank and stocking. You will never grow more BB than the wastes from your fish can support. So, you stock your filter as per how you've set up your tank. If you want to "polish" your water you can add more sponge, or floss, or pads. If you have a more heavily stocked tank, you'll want to use the space to beef up your bio-media.