I am wanting to construct a duck and fish pond and make a good one. I am hoping to get both ducks and geese next spring and while they don't NEED swimming space I'd like them to have it. I don't know gallons or size but I would want one that could sustain probably about 20 or so birds swimming but will be more rectangular than even. We have a backhoe and all that so no problem with that. I have read Wifezilla's wonderful post on duckponics/ponix so I know about the filter system I'd have to use plus I worked in a fish shop and learned A LOT there. I would be filling it up with a bunch of feeder goldfish that I can get ridiculously cheap and they will eat some of the bird poo. What do I use to line the pond when it is large size? We live on site of our grain facility so there is considerable dust/rice hulls/chaff that gets blown around. Is there a way to combat this? Will the birds eat the fish? Will this attract other animals that I don't want? I don't mind frogs and such, but I don't want any turtles!!! We have a canal semi-near where I'd be building it. Can I put crayfish (crawfish or crawdads around here) in there or does that pose the same problem as turtles? Will the ducks or geese eat them or am I better off just harvesting them from other sources for the birds and keep them out of their water? And lastly (for now) If I put in a pump for a water feature (separate from the filter) will it disturb or be disturbed by the birds?