I heard that you only need to turn your total volume over once every two hours.

I have 7 or 800 gallon and I have a 2400gph pump. I am more interested in the waterfall spill rate and it looks about right. My Laguna pump is aledged to be effecient and only 100 watts. They are a little more expensive.

I've always read where you shoot for turning the pond's capacity over once every two hours, but also heard " more is better" and many shoot for 2x that amt.

I planned for a 2000 gal pond and after head loss on the pipeline, etc. my two 3900 Laguna mag drive pumps probably are putting 6000 gal/hour over my falls (when I have both pumps running). I don't think it's excessive, but I have a wide weir.

Mag drive pumps are more energy efficient and safe (no oil). I'd go bigger, 1200 gal/hr.

Good Luck!

My pond is about 950 gallons. I have been using 2 separate 500 GPH pumps. I had a turtle which puts out LOTS of waste. However, he didn't survive the winter so I am considering cutting back to one pump. I have done pretty well with water clarity and couldn't remember the last time I lost a fish. I don't have water falls though, just a skippy filter. I would think you would do great with the 950. Could probably do even less unless you have a really heavy fish load.

My pond is about 900 gallons and I have a waterfall. I am using a 3100 gph pump, but with some pipe friction and head loss, I am probably turning the pond over twice an hour. So far, so good.