After my last post, its responses, and a long convo with one of the best pond builders around, I have gotten a better idea on what I would like to do. The basics are still there...4 by 4 post walls, well reinforced on a cinderblock base with gravel to avoid prolonged exposure at the base to moisture. This will be 12ft long, 8ft wide, 4ft deep. This will give a rough 2900 gallons. Water will be pulled through a skimmer and bottom drain. Water will run through an Evolution ES 5500gph pump with priming pot/trap. I am unsure on the filter. I see a Fishmate 9000gal with 36w UV but i am not sure how well of a filter it is. Water would then return to the pond two ways. The first will be a series of pressure heads on one end to create a small swimming current. The second will go to a trough on top of the pond that will be the 12ft length and contain three spaced water falls. The trough will be lined and contain Siporax, Calcium Reactor Media, gravel, and some small plants. Thoughts? Suggestions on the filter? Suggestions on the design?