Garden waterfall pumps come in all shapes and sizes. This article will help you learn what to look for when planning your backyard water garden, so you can create the feature of your dreams.
Before we start the discussion, it’s a good idea to have your pond on its own dedicated GFCI protected electrical circuit. Some larger pumps can draw quite a bit of power.
First thing to do is decide what kind of pond or water garden you want. Are you picturing a quiet trickle, so you can still hear the birds singing, or a rushing falls that creates a lot of white noise. Remember when choosing a garden waterfall pump, you can always place an inline flow valve to adjust the rate of water flow. You can always slow the water down, but you can not make it flow faster than the pump will allow, so be sure to get a pump that surpasses your needs if possible.
When I built my pond, I didn’t realize the impact a rushing waterfall would have on the noise level. Now my backyard is filled with white noise. It’s a soothing sound, but I don’t hear the birds singing … or the kids arguing, so it’s not all bad!
Submersible waterfall pumps are measured by gallons per hour (gph). The higher the gph, the more powerful the pump. There is also a measurement for head height. This is the maximum height that the pump can pump from your skimmer box to your waterfall feature.
Think of it like driving a car. When you are driving down a flat road, you keep your foot on the gas at a minimum to maintain your speed. Now when you approach a hill, you have to step on the gas to maintain the same speed as you ascend. Using this logic, you will need a pump that will push enough water through and up so you can achieve your desired result. This is known as head.
When doing your final calculations, know that you will need 1′ of head for every 90 degree turn in your line, as well as 1′ of head for every 10′ of length in your return line.
Depending on the type of waterfall you desire, decide on a flow rate. Then you multiply your GPH by the width of the spillway. Here are some examples of a typical 24-inch wide waterfall spillways at different flow rates:
When designing and building your pond, you also will need the proper sized water line. The larger the line, the less restricted the water flow. In other words a 2″ water line will push more water through it than a 1.5″ water line, regardless of the size of your pump. Your system will only be as powerful as its weakest link. If you have a powerful pump and a small water line your flow will be hindered, as well as a large water line and a weak submersible water pump.
Below is a chart for the recommended size water line to be used for a waterfall return line based on your desired flow rate:
Using all that we’ve discussed above, its time to put everything together before you make your choice of which pump to purchase. To calculate it use the following formula:
Height of the waterfall + 1′ for every 90 degree turn + 1′ for every 10′ of line used
This means you will need a pump that has your desired GPH at the given feet of head. For example:
For a moderate flowing waterfall that is 3′ high and has 2 elbows and 15′ of water line, you will need a pump that produces 3,600 GPH at 6.5′ of head. This can be found in the specs of any given pump you intend to purchase.
Another thing to be sure of, is that your pump is circulating the water completely at least once every hour. To be sure this happens get a pump whose GPH exceeds the volume of your water garden. One cubic foot of space takes 7.43 gallons of water to fill. Knowing that, depending on the shape of your pond, use the following formulas (all calculations are done in feet)
For a rectangular pond: length x width x average depth x 7.43 = Total volume in gallons
For an oval pond: 0.8 x length x width x average depth x 7.43 = Total volume in gallons
This helps to maintain a healthy pond. Also, moving water cuts down on mosquitoes and other pests.
Now that you know what you are looking for, here is a comparison of some popular garden waterfall pumps, submersible and ready for action . Any one of these will get you started in the right direction.
We are comparing a few different style pumps all with similar GPH to compare. It’s good to compare “apples to apples”. The head height to GPH ratio chart for each pump is for the whole family of that brand of pump.
I’m only comparing pumps that are in the 5200 GPH range, because that is what I am most familiar with. That is the GPH of the pump featured in the how to build a pond tutorial.
Alpine pumps come in wide array of sizes to meet all of your needs.
This pump also features a variable water flow controller, so you adjust flow rate on the fly!
Aqua Pulse 5200 GPH Hybrid Drive Submersible Pump – Up To 5,200 GPH Max Flow
MS5200 5200GPH Submersible Fish Pond Pump (This is the pump used in how to build a pond project)
Whether you decide on a babbling brook, or white water falls, your garden waterfall pump is truly the heart of your project. It’s what brings your garden pond to life. This is about you and your vision of the little piece of paradise you will be creating. If you have any first hand experience with any of these products, or have a suggestion for a better one, please leave a comment or question below and i will be happy to get back to you as soon as possible. Best of luck with your projects!