Knowing how to select the correct waterfall pump for your pond can be a difficult task. There are several variables to consider, but this post will help make your selection simpler with 4 steps. You will need to know 4 factors when selecting a waterfall pump: the width of the waterfall, the water flow you would like, the height the waterfall will sit above the rest of the pond, and the distance from your pump to the top of the waterfall.
1. Width of your Waterfall
This should be fairly simple to determine. If you already have your waterfall built simply measure from one edge of the waterfall opening to the other to determine the total number of inches your waterfall covers. If you are still in the planning stages of building your pond or adding a waterfall, you can use a spillway to simplify the construction of the break of the waterfall. Once you have the width of your waterfall in inches, write that number down. As an example we will use the waterfall in the picture to create our measurements.
Example: The width of the spillway is 16 in.
2. Water Flow of Your Waterfall
For determining the water flow you would like to see from your waterfall, think about what you are visually anticipating your waterfall to look like. Also consider that this will be a primary source of the beautiful sound of moving water. What kind of water flow would you like to hear as you are near your pond? The three primary categories of water flow we like to describe as a trickle, sheet, and Niagara flow. A “trickle” flow will have short breaks in the water flow as it fall over the edge of the waterfall. A “sheet” will be one smooth an even flow of water. The “Niagara” flow will be a heavy flow of water that that will produce the most sound of moving water. If you choose “trickle”, multiple your number from step 1 by 50. If “sheet”, then multiply by 100. If “Niagara”, then multiply by 200. This calculation will result in the number of gallons per hour you will need your pump to be able to turnover.
Example: The flow of the waterfall is a “sheet” flow, so we need to multiple step 1’s width by 100.
16’ x 100 = 1,600-GPH
3. Height of your Waterfall
The height of your waterfall can be measured in feet from the surface of the water in your pond to the break of the waterfall. You may have or would like a waterfall that sits further back from the pond and cascades down a water course, so for this measurement, you will only need to measure the vertical distance. If you have not yet constructed your waterfall, make an estimation for this step. For most backyard waterfalls 1-3 ft is a typical height range. For the next step, you will need to know how far away the waterfall is away from the waterfall pump.
Example: This waterfall’s height is 3 ft.
4. Distance to the Waterfall
For this step, measure the length of tubing in feet. Start from where the tubing exits the pond to the top of the waterfall where it ends. For this step, we are measuring water resistant, and the water does not experience resistant until it is in the tubing above the water. For every foot of tubing to the waterfall, add 10 in to your measurement from step 3.
Example: The distance of tubing used 3 ft, so we need to multiply that by 10 in.
3 x 10’ = 30’ (or 2’ 6”)
And we need to add that to our measurement from step 3. 3’ + 2’ 6” = 5’ 6”
Combine your information to determine your pump size, so for this waterfall we will need a pump that is able to pump 1,600-GPH at a height of 5 feet and 6 inches. Look at the flow charts below to determine which waterfall pump is best for you.
For our example, the PW2300 model is the closest fit, so we selected that. You can also find the flow chart on the side of the pump packaging at your local retailer. Now that you have your waterfall pump determined, you can start enjoying a beautiful waterfall!