What kind of pump should I put in?

The most important thing to take into consideration is the amount of water you want to move. For the health of the pond, you need to change or cycle the entire pond every hour. This means if you have a 500 gallon pond, you need a 500 gallon per hour (gph) pump to circulate the water. If you want to have a stream or waterfall, this is not sufficient. A simple ratio to figure out the size of pump you need is: stream/fall width x desired depth of the water in the stream x 50. For example, if I want an 18 inch wide stream, 2 inches deep, the calculation looks like this: (18x2) x 50 = 1800 gph.

This leads you to the next question: Which type of pump should I buy? An out of pond pump or an in pond or submersible pump? Do not buy a swimming pool pump or a Jacuzzi pump. They are inefficient and will cost a lot of money to run.

Submersible pumps are the least expensive to buy, but the most expensive to run. A 3900 gph pump you can buy at Home Depot will cost you around $190 to buy. It will use about 700 watts of electricity. There are new generation pumps that will use 175 watts of electricity and pump 3900 gph - they cost $250 and up. Inexpensive submersible pumps also clog easily since they have a built in screen to keep leaves and other junk out. More expensive pumps will not have the built in screen and can suck junk up to 1 inch in diameter through them. They do have advantages compared to centrifugal pumps in that they are quiet. Because they are in the water, you will not hear them.

Centrifugal or out of pond pumps cost more than submersible pumps (about $350 and up), but they run on less electricity and pump more water. They last longer and have fewer mechanical problems as well. These pumps will pump up to 10,000 gph. These type of pumps will produce a slight whining sound as they run so keep them away from areas that have seating for pond enjoyment. Here is a good site to compare and look at different pumps . Check out their pump comparison chart. It contains wonderful information comparing volume and electrical wattage consumption.Do not forget about running electricity to the pumps. It would be smart to run the wire in 1/2 inch PVC electrical conduit piping so later you do not accidentally cut into the wire and electrocute yourself. Place the GFCI outlet in a water resistant enclosure 3-6 feet from the pond and at least 1 foot above the ground. Check with your local city codes for exact requirements.

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