AQUAEL Fan Filter Mini Plus. Help Please To Customise

The website doesn't say anything about the sponge being impregnated with carbon, always a possibility with black sponges. I've never seen that 'inlet tube' idea before (looked at the manual). But it should be easy to customise if I understand it correctly.

Would it be possible to cut up the sponge into several bits? Then place a layer of filter wool where the water would flow through it last, and sandwich the ceramic media between two blocks of sponge? With the ceramic media sandwiched you wouldn't need to put it in a bag which could be tricky if that inlet tube goes right the way through the sponge. But it would mean taking it apart very carefully when cleaning so you didn't lose any bits. If you wanted to use a lot of ceramic, just use two thin layers of sponge to keep the bits in place.