i would use carbon. i dont know where you got the tank from or if youve had it for a long time but if its been sitting empty or someone has used medications in it there may be some residual contaminants and the carbon will remove them. the only thing itll hurt if you decide to use it is your wallet and its not that expensive. i use zeocarb cause it converts the ammonia to a nontoxic form through an ion exchange process and its mixed with carbon. and the only point i was making about cycling was that there will be ammonia build up initially and to have some in the tank will not kill the fish. just test the water and if its high change the water. if you dont overstock it you should be able to get away with a weekly water change to temporarily remove ammonia until the thank is cycled (usually about a month) and depending on your stock level you can adjust the maintenance. dont get me wrong its important but it doesnt accomplish anything a water change cant. obviously other than bacterial conversion.