I am pulling about 5 feet uphill on the suction end and pushing about 16 feet uphill over a total distance of about 475 feet. Total lift about 21 feet more or less. I estimate I am getting about 3,500 gph out of a pump rated at zero head 9,060 gph. I have been running at 3/4 throttle. Full throttle gets me very little water gain, and is much louder and uses more gas. Friction losses in the pipes I suppose. However, my pipe is very slick and looks like teflon lined on the inside, and there are four non restrictive splices due to the fact that the pipe was scrap and pieced together. My estimates are based on how much it raises the pond, and may be off somewhat. I have about 50 hours on this 2 inch Harbor Freight pump now, and it has performed flawlessly. The gas tank is too small is my only complaint. I paid just under $200 total for it new including a one year full replacement plan.
