Newly aquired used hob filter

[Franwjr]

I recently was given a whisper 60 HOB filter. Unfortunately there was no filter media included. I know from having other tetra filters that you can easily replace the poly bag that stores the carbon inside along with the frame that holds it in place, but what is the best way to replicate the biological media sponge that would rest along side it.
I thought that maybe I could put some bio media in a filter bag and wedge it in the filter, but I was curious of any other suggestions.

 

[gravereaper0]

Why don't you just throw some ceramic rings into the hob before the filter.

 

[njvgl2090]

you can buy cut to fit type foam or pads also