People make recommendations based on personal experience. So, I would like to recommend “Mag Pumps” made by Danner Pondmaster. These are magnetically driven pumps, contain few parts, and consume less electricity than some other types. Consequently, fewer problems.
These pumps just keep going, and going, and going……..!. Of course I can’t make the claim that they “never break”, but we had ours for many, many years and they always worked without a problem. Really amazing!
Naturally, there are different size pumps for different size ponds. The larger your pond, the larger the pump you will need. For our 3000-gallon pond, we had a pump rated at 1200 gallons an hour. Once you know how many gallons of water your pond holds, then you can get your pump. The quick formula for figuring your pond volume is LENGTH X WIDTH X DEPTH X 7.5.
If your pond is fairly large you may want two pumps, especially if you have a waterfall or fountain. If you are interested in getting the full scoop on pumps I would recommend you log on to Google and type in: selecting a pond pump.