I've started digging a hole for my pond and have been reading through all the different threads about peoples ponds and wondering how I'm gonna keep things clean. I've got 6 Khaki Campbells and boy are they messy! I was sitting here on the couch a night or two ago, looking at my 50 gallon fish tank and was struck by inspiration, I hope. I have pretty good depth of substrate (gravel) on the bottom and although I'm terrible about cleaning it, my fish have always thrived. The gravel makes a great filter so to speak for solid waste and the pump and actual filter keep the water nice and clean. What if I were to do the same thing for my duck pond? I could dig it a good foot or more deeper than I want it and add a thick layer of gravel...wouldn't that work to keep the water clean? I, of course, would still have a regular filter/pump (I'm looking at one of the home-made filters...trying to keep costs down), but I'm thinking the gravel would really work to keep the solid waste contained. I would love to hear other people's thoughts on this. I need some of that great wisdom that is so plentiful on this board. Thanks!