[m-jackson]

I am just curious why you would even bother with the original filter cartridge. Why not just stuff the first with sponge material and the second with charcoal if that's what you want. If I was going to try this I probably just use sponge in both. What you really are looking for is somewhere for the bacterial to grow. If it was not so expensive I have a couple of aqaupure 802 sitting around. I like to use them in my rental house as they almost never change the filters. If the wall bracket is similiar to these you could even use it to hang on the back.