I wouldn't change anything at the moment if what you're already running in it does nicely, then I'd just keep using that. Does it come with another media chamber that you didn't have access to before? If it does, then maybe I'd think of running another sponge or something. If it ain't broke, then there's no need to fix it. Now that you've upgraded it, you can probably experiment with switching one element out at a time and see how it affects your levels if you're looking for a specific result.