pond biofilter -- We're thinking of adding a small flock of ducks to the homestead for eggs and meat. With that comes the need for water. I'd love something a bit nicer and more natural than just a kiddie pool so building a small water feature is ideal. Adding a small DIY bio-filter system that can be utilized in the small pond, water plants (which feed on waste products in the water) furthers the eco-balance we are working towards.