My system which is a basic Berlin system Berlin Method - Wikipedia, the free encyclopedia is as follows: Refugium with LR Chaeto and TONS of Kenya Tree, protein skimmer, thats it... All the bacteria needed are in the sand bed (about 3" deep), and the liverock. Oh and I do filter the effluent through a filter sock. Never needed more, except when I was using some LR ordered through the net, THAT I suspect was a bottomless source of nitrates IME... Most people around here don't use wet dry filters. I would like to add a GFO reactor sometime, but my current situation won't allow it (I'm broke).