wouldnt use it unless you have a power filter ie H.O.B. hang on back or canister. as for the ugf do you pland to use that for ranas. i hate to knock peeps setups but it is not recomended ranas produce to much waste and youll end up with one mess of a clogged filter.
Active Carbon is usefull in helping cleanse ammonia, chlorine, and clarity of the tank. They're considered as bio media which you add to your filters or substrate. DONT add it inside to the tank, after awhile carbon looses its purpose and will have to be replaced again, so you dont really want hundreds of carbon particles mixed in with your gravel/sand.