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The JBJ nanocube is a decent unit. I have the 12gal deluxe model set up as a nano reef and am pretty happy with it. The three stage filtation in the back is pretty good as long as you do not use the sponges, bioballs or ceramic rings the unit comes with. Just fill up the chambers with LR
rubble instead. It is a much better filtration media. For the same amount of money you may be able to set up a 29-38gal tank and just buy the accesories. Since this is your first SW
tank I suggest the first thing you buy is a copy of "The Conscientious Marine Aquarist" by Robert Fenner to help you get started. Keep in mind that the 24 gal
nanocube will only support three or four very small fish. Look at firefish, clowns, royal gramma, sixline wrasse or various gobies as options.