Just received the new pump and couldn't wait to play with it. This is about a 5' tall column thru a 1" i.d. pipe. A few words on pumps... I originally went to Home Depot with the idea of using a Sump Pump. I figured they had enough horsepower to really move some water, and they do. However, I started chatting with the guy in the plumbing dept. and discussed what I was doing with the sink, etc. Well he told me it was not a good idea because first off they are not very efficient. Also, these pumps are made for intermittent operation and the bearings would not stand up to continuous operation.  Then, and this was the clincher, when these bearings failed they would leak oil into the water, which, unless your pond is in Jersey, would be very bad for the fish. Then he asked me to ask him how he knew. As you can guess he had this very same thing happen to him. It's great to learn from other people's mistakes for a change.