About Your Pond Pump

With getting the right pond pump, there are some things you have to take into consideration:

You’ll be money ahead and satisfaction ahead to take your time with the pond pump choice. It is the heart of your pond. And if you try to buy a pump from a dealer who can’t answer the following questions – run! Fast!

Correct pump sizing depends on:

Calculating the “pond pump head”.

The “head” is roughly defined as the height the pump has to move water upwards. If your waterfall is three feet above the waterline and your pump is two feet below the water line, then you have a “head” of five feet.

Calculating the proper pump flow rate.

You’re going to really hate yourself if you don’t get this one right. If too low, your waterfall will look anemic and dripping. If too high, you now own Niagara Falls and it will look like overkill.

You want a flow rate of approximately 1500 gallons per hour for every one foot width of your waterfall.

So if your waterfall width is 3 feet, you’re going to require a pump that delivers 4500 gallons of water per hour.

Why did I italicize “delivers” above?

The reason is that the rated pump rate on the pump is NOT what will be delivered in your pond. And isn’t that a pain.

A rating is delivered based on water-in and water-out with no head or restrictions. It doesn’t take into account “head” and the restrictions imposed by pipe sizes, length of pipe run from the pump to the waterfall (the longer the run the more friction and bigger pump you’ll need) and other construction issues such as 90-degree elbows versus smooth corners.

You are not concerned about the pump’s manufactured rating, you are really concerned about a factor known as Total Dynamic Head.

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This is the measurement that takes into account all the factors of your individual pond – how high are your waterfalls, how long a pipe run (and what size pipe?) from the pump to the waterfalls.

And all these variables stop a simple web page from giving you a real answer (and any web page that pretends to is one to avoid).

So the real trick is to go to a pump store that has the calculators on their computer to figure out the TDH for you. (You want to be a math whiz to begin to do it manually and I’m not).

What you want (in the above example) is a pond pump with a TDH rating of 4500 gallons per hour - not a manufacturer's rating of 4500 gallons per hour. And that TDH rating will depend on your unique pond and its construction.

If your pond pump store can’t do this – then find one that can. You’ll be happier in the long run.

If you're installing a very small pond or want a summary of pond pump sizing for small ponds then you should visit this page.

And if you have questions about pond air pumps, you might want to check out this page before you spend any money.

Some of you would like to consider solar pond pumps so here's a discussion about this kind of pond pump.

Smaller ponds are often sold with submersible pond pumps but the external pond pump is a much better choice for any pond larger than 1000 gallons.

Need some good water garden construction pictures?

But if you do have a small garden, here are the things you should consider when looking to buy a submersible pond pump.

A few of you are probably looking at one of the simple pond pump filter combinations where the pump and filter are molded together. Here's my analysis on this machine class - it is excellent for a specific kind of pond (but not much good on others).

Questions and Answers