haha . Well brutus is just stating the truth. There isent much else if you dont want HOB
, Canisters, undergravel, or a sump in the case of SW
.. you really would have to do 100% water changes or i dont know.. keep a tank full of water and nothing else.. before you go all defensive think about what your saying.. theres no real logical answer to what your asking.. you cant keep a sustainable aquarium without some type of filtration especially on a tank of that size. period.