Fluval 306

Plants or no are not a major factor for the media. I look at what I want to do for any fish and the plants go along with that. I think of media as straining the chunks first, then strain the smaller stuff before the water goes to something that has lots of tiny holes, etc. where bacteria can live apartment style. Then I may run something like floss as a way to "polish" the water for best appearance. But all tanks are different and you may find you want more of the bacteria stuff if you have lots of fish or more mechanical strainers if the water has stuff floating around like dust, etc.
It takes a bit to get in mind what works best and canisters are great for letting you decide what and how much.
Round barrels to stop leaves, then course sponge, bio media, then floss is one way I go. Water ususally runs up from the bottom to top and then to the tank.

Cool thanks for advice.

Glad to help. It can be as simple as using what comes witht the filter but then if we get into needing something else, there are lots of ways to adjust it. I rarely use carbon that comes with filters but lay it back in case I want to have it for special stuff. It does a good job but it stops up in couple weeks and needs more messy attention than i want.
Outside of that, I just do my best to keep all the little bacteria happy and give them lots of housing options. If I have plenty of bacteria to due the ammonia process, I use the rest for "straining" the rest for appearance. I tend not to be too fussy about the water olok so lean away from stuff that sogs up to quick like filter floss.
I like this type stuff for "cut to fit" things.
I buy from these guys quite a bit and like their blue bonded pad and the black foam. Much cheaper than ready made.
https://www.petsolutions.com/C/Floss-Foam-Aquarium-Filter-Media/I/Bulk-Filter-Media.aspx

I've been running a 306 for several years, it's been a reliable and solid performer. The black coarse bottom tray filters are solid but I supplement them with medium grade filter material placed on top of them in the same tray. I use bio media in the middle tray along with 2 Purigen bags on top and more bio media in the top tray. I no longer use the fine polishing pads/floss anymore, in my experience these clog and compress way before the bottom tray filters need cleaning and reduce flow.