filter media question

[jcoat]

I just have a question about my filter system. i currently have a emperor 400 hang on filter for my 29 gallon. It has two filter as well as two gray containers in front of the filters. I was wondering if I should be putting carbon or something in theose gray media containers? if so what should i be using?

[bertoni]

I would use the filter to run activated carbon, and not use the other media. If the tank is running and has livestock, though, a sudden filtration change is not a good idea.