Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Mag drive is one step better than the older pumps, Hybrid is even better.
Mag drives can usually pump the water to higher levels, so a chart showing head loss might look better on the mag drive, but you are not wanting to pump the water 10-20' up! A chart for a hybrid pump will not look so impressive after a fairly low cut off point. They are great at the lower head heights, though, which is exactly the height of most pond and stream set ups.
Look at the head loss at just a bit higher than your waterfall. Perhaps 50% higher, maybe not even that much. Pressure loss in the pipes can be minimized by going with larger diameter pipe, and Hybrid drive pumps benefit a lot from this.
When in doubt, a larger pump is better, because you can add a ball valve to reduce the flow, if you need to. In all the ponds I have built, pumps never seem to put out as many gph as they are rated for. If you wanted 2 pumps you might make them add up to about 2000 gph. This is a very good way to save electricity. 1000-1500 gph is very good circulation for fish and filter, but may not be quite as impressive a water fall. Adding a pump that discharges just above the water fall would make the water fall sound better.
Another filter option, look into a 55 gallon drum. This can be hidden somewhere near the pond, or even buried near the top of the water fall (perhaps in the hill you are building to make the water fall). Just make sure you can drain it through the bottom to flush it out once in a while.
Make the water shoot out into the air then fall into the pond. The hollow behind the falling water makes an echo chamber that intensifies the sound. Makes a much more impressive melody that just a rippling stream.