I prefer media with a higher "USEABLE" surface area. I find that ceramic plugs and you're left with only the surface area on top. I would use the foam that comes with it, and fill the center with plastic pot scrubbers. There is ton of surface area that can actually be used on those. I love them. Better would be to cut additional 20 pore per inch foam and put in there, but this is much more expensive and difficult. The water must be forced through the media and not be able to go around it.