I got a Tiger Oscar (growing quickly) in a 200 litre tank with a Fluval 205 canister filter which is working well. It was originally set up with the filter media that came with it but I see from the manual you can get various types of filter media. Namely, Ammonia remover, BioMax, carbon, peat granules, Zeo-carb, etc.

The canister has three compartments the question is which is the best mix for keeping an Oscar?

Personally, I would go with BIOMAX in all trays. This is your biological filtration and is the most important part of your filtration system. Try and get as much in your filter as you can. Also put some pre-filter media in as well to catch the waste. You could go with a polisher just to sift out all the tiny particles. You have to bear in mind that you will probably have to change this every week because it will become clogged very quickly because Oscars are so messy. Personally, I would leave it out and just go with the prefilter media.

www.aquatics-online.co.uk/catalogue/hage...val-filter-media.asp

Thanks, I didn't think of having the same in all baskets.
The water is very clear at the moment but it does have carbon in one of the baskets.

Fluvals come with carbon (the fine black stuff in the bags), remove this. In the trays you can use biomax or the hollow tubes or the rocks that look like sponges(holes in it) or the other types available. You can even use the stuff they sell to go in those round tanks. All that matters is that is has a large surface area. Forget all the other types you mentioned

As for the polishing pads, ofl is right, you will be cleaning them every week which makes them a pain, and you dont need them