With the Emperors comes two spare plastic cartridges. I just load these with aquarium filter floss. Works well for me. In any event after a couple of weeks or so, the carbon in the stock pads will become inert and you can just keep rinsing them in old aquarium water. Be careful of taking them apart as it can be a bit messy. Jeff
In theory there should be no difference between theory and practice. In practice, there is.