I've been wondering is it better (cost, efficiency, quality,etc.) to buy third party media for my canister media bays. I've been thinking of buying mesh bags and filling it with marineland diamond carbon and other such medias instead of buying fluval brand media. In terms of quantity, i do get more carbon for the money cause i can get 68oz of carbon for less than $20 but the fluval pre-packed bags cost about $15 and its only 3 bags per pack. i'm not sure what to do right now and for other types of medias. can anyone help?

Oh yeah that is the best way for canister filters. I never buy the brand name stuff they want cause they want the $ for it and if you can do it your self, save alot of money that way. Also look on line for a cheep cost of things too