I have a couple 302b models.
I put filter floss and a little blue sponge in the bottom (I dont know if yours came with a sponge) it filters from the bottom up so you definitely want your mechanical media in the bottom.
Chemical media is your call. Alot of people dont use it at all.
The bioballs are nearly useless in a canister filter due to their disappointing lack of surface area. you'd be better off using a handful of aquarium gravel Instead almost lol.
The ceramic rings that were shipped with mine didn't look very porous. My fluval rings have more texture. I'd head to the local fish store and buy a couple 500g boxes of biomax. Or if your in a monetary bind, grab a few packs of pot scrubbies.
Don't overload the baskets too much, mine are kinda flimsy, make sure they stack nice without being forced.
I read some articles/reviews and the model you bought pushes close to 200gph with media and head height factored in, which is awesome. Great filters for the money.
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