i want to buy a fluval fx5 and it comes without media (includes just the sponges), and to my knowledge there are few different media available. my questions is what media should i buy to suit my tank (72"18"24), keeping in mind i will be growing just 2 oscars.

please check it first. FX5 usually comes in a ready to use set up.
sponge is for extra use in the suction area. the canister is
supposed to contain all 4 kinds of media inside.

it comes with 4 simple spunges...actualy what exact kind of media should it have ??

I dont have a FX5 but i do have fluvals 404's,204 and some 405's. These filters come with baskets to put media in. If the FX5 has baskets then any standard media will do. Example are the hollow tubes, the little rocks that look like sponges and the irregular shaped rocks. What you need is anything with a big surface area for its size that will fit in the baskets. If the baskets are real big then maybe them plastic balls will work. Im sure a FX5 user will chime in

I hate to say this but im sure a shop will help you chose some media (I just hope its good advice, the shops often give very poor advice)

i would buy the plasti " BIO BALLS" as the surface area of one ball is far greater than any other media available ......

i have mine filled with bio max and a fine filter pad on the top

I got my Fx5 today, started to put it together and I noticed these ball type plastic things. (link bellow). do I put them in the filter basket and if so in which one? and in the other two baskets what should I put suitable for oscars and to make the filter run more efficiently?.

i760.photobucket.com/albums/xx243/cvl1919/SDC11869.jpg

id be tempted to put them in the bottom basket,bio max in the second,and more biomax in the top with some fine filter wool over the top...In mine i put alfagrog in the bottom and middle with bio max in the top with filter wool!!

the fx5 flow pattern is from the bottom to the top. meaning that the water come into the filter and rises from the bottom of the canister and exit from the top.

in mine i use a blue fine filter pad from fluval to catch the larger particles and then fill the remaining baskets with fluval bio max. there is really no reason to add a prefilter or carbon to the system.

Yep necromancer is correct,i use the fine filter wool as a polisher at the top just to catch the tiny little bits that get through all your other media,basically leving the water crystal,as mentioned it's not needed but each to there own!!

thanks for that.. you all do make a point.. thanks