There are many types of Macro Algae, I think most folks tend to focus on the common 3 (Chaeto, Caulerpa, and Dragons Breath). There are many M.A.'s that make a nice addition to your D.T. if the refugium in the sump idea doesn't work. I have Pencil Cap, Christmas Tree, Mermaid Tail, Red Grape Caulerpa, Halimeda, and Flame Algae in my shallow softy tank so I still get the nitrate reducing benefit of having a fuge, my MA just happens to be in the DT.