quick question.. lets say you have a small pond. Normally a biofilter weir would be used for filtration with some kind of media in it..bio balls/blocks etc.. and only takes up a small area. Why does building with a bog take up such a huge area in comparison? I know you want room to grow plants to help filter. Can you make it smaller and just add a bag of bio media in the pump chimmey? Just curious.. I really love the look of bogs and the concept..