bought a better filter, got it for twenty dollars and cheaked the inside, it's filled to the brim with fishy poop! i have no idea what carbon and stuff they use
I'd just clean out the entire thing. Throw out all media and stuff and start fresh with new ones. You should be able to find stuff online for the fluval.
i don't wanna post pics but the bottom of the bucketi used to clean out the sponges (there like $20 per pack, so i'm gonna reuse them) and i've looked online and can't find what type of carbon they need, there little black pellets and there are some big white ones with holes thou them
And you could probably just use any brand of carbon. Just put it in a media bag and place it in your canister filter but I don't know for sure because I don't own any canisters.