There is a much easier way to deal with this.
Get an AquaClear filter sponge in a size larger that the filter box of your HOB. Toss all your cartridges in the trash. Cut the Aquaclear sponge so it fits snugly into the filter media area of you HOB. Leave 1/2" of open space under true sponge to aid circulation.
All you do going forward will be to squeeze out the some in water remove during water changes (Old Tank water). The sponge will last for years. I have done this for over 20years in all my HOBs, a pond, and a reef tank sump.
If you ever need chemical filtration. You can put some Carbon in a bag made from a woman's nylon stocking. Place the carbon bag under the sponge. Of course the sponge will ride a little high in the media box while running the carbon bag. That is a non-issue.
This is a Sponge replacement I cut to fill the unused Chemical Media container in am Fuval G3
Last edited by DogFish; 11-17-2012 at 11:51 PM.
Reason: add pic