When it comes to maintaining pristine water quality and a healthy ecosystem on a medium to large body of water, nothing does it better than a wetland filter. A wetland works just like a biological filter, but instead of creating a waterfall; it creates an area in your pond thick with naturally-filtering plants, as well as rocks and gravel, which provide a surface for bacterial colonization … nature’s perfect filters. So a wetland, while naturally beautiful and pleasing to the eye, is the ultimate filtration method, and will help keep your water looking crystal clear.