I got one of the Aquascapes pieces of literature in the mail recently, and it showed snapshots of the progression of Greg Wittstock's 'pond', covering 1.5 acres, if I remember correctly. How do you keep a pond that size full of water? I've used the auto-fill valves that come in kits, but a pond this size would need much more water, I would think. Do you have to tap a well just for the pond? Steal from the nearest hydrant from time to time? Thanks for any insight.