I intend to build a decent sized little pond for our ducks this spring. I will make my own liners and all that jazz. I know ducks are dirty animals in their water. My questions start with this: If I make this pond deep enough, it probably will be anyway, would intorducing fish that are bottom feeders like plecosthemus and others like that be sufficient in cleaning the duck feces in the pond? Has anyone tried this? Another question is how many square feet should I use if anyone would know this. I have a valley picked out not too far from our house and this pond is going to be made from an earth backdrop that I will have to put in but i want to make sure that I use enough room to make it big enough for at least a dozen or maybe 2 dozen birds.