Waterfall pumps are an essential element in maintaining the beauty of a backyard waterfall. They are crucial for providing the necessary water flow to make the waterfall look and sound natural and the required aeration to keep the water clean and healthy.
When part of an ecosystem, the moving water of a waterfall also promotes the development of good microorganisms that control algae growth. In other words, a waterfall pump adds to the overall harmony of a water feature.
Selecting the right pump will allow you to enjoy your garden water feature to the fullest. But with the wide range of waterfall pumps available on the market, how do you know which one to choose? Here are the main factors you should consider.
Type of Pump
What type of pump is used for waterfalls? In most cases, there are four main types you may want to consider.
This type includes an impeller linked to the motor shaft. Its power is its main advantage. When there is a high head pressure condition, a direct drive type may still deliver good flow.
There are also direct drive models for “solids handling” or “filthy water.” These are simple to maintain because little particles are pushed through without clogging the pump.
Their main disadvantage by far is the rise in operating costs. Also, they frequently don’t last as long since the motor’s seals deteriorate more quickly when too small for the task.
Mag-drive models have an impeller that is connected to a magnet. The impeller rotates when the pump is running because of the rotating magnet. These work well in low-head situations but are not strong enough to withstand high-head pressure. The key benefits of these pumps are their long lifespan and low energy use.
A magnetic field rotates the impeller on this pump as well. The magnet is not, however, affixed to the impeller directly. Its design ensures that the rotor and impeller spin in the same direction every time the pump is turned on, as opposed to a magnetic drive model. The blades are thus curled as opposed to straight. It enables asynchronous models to operate at flow rates and efficiency levels that are far higher than those of mag-drive types.
The electricity consumption is comparable to that of a mag-drive model. The design’s primary flaw is that it requires a little more maintenance to keep the rotor clean, or the pump is likely to overheat or stop.
Although they come in a wide range of designs and flow rates, external centrifugal models need a little more piping and planning. They also frequently cost more, but they undoubtedly offer advantages.
External centrifugal types typically give you more power while consuming significantly less energy. Moreover, these frequently have very long lifespans.
The right flow rate for your water feature may depend on a variety of things.
Size of the Pond
At least half of the water volume per hour needs to circulate in a pond with plants and fish. If your pond has 2000 gallons, for instance, you will need to pump at least 1000 gallons every hour. Koi ponds, on the other hand, call for more frequent water circulation, with the minimum being one full volume each hour.
Basins with a capacity greater than 5000 gallons may start to slow the turnover rate. Thus, an 8000-gallon basin requires at least 4000 GPH, while the prior general rule of thumb suggests that you might be able to get away with less. An air pump could also be used to increase the aeration.
To create the typical waterfall look, you’ll need a flow rate of 100–150 GPH for every inch of waterfall width. In other words, if you wanted a 30 cm waterfall spillway, the pump would still need to produce between 1200 and 1800 GPH, even if the pond was just 1000 gallons. For a heavy flow, use closer to 200 GPH per inch or closer to 50 GPH per inch for a trickling effect.
For most of the additional pond equipment, including the filter, skimmer, and UV clarifier, the manufacturer may give a minimum and/or maximum rating. It is essential to adhere to these rankings.
Head pressure, a form of resistance the pump must overcome, can lower the total flow. To calculate the total dynamic head (TDH) pressure, you must consider several factors and use the flow chart provided by the manufacturer.
The first step is the simplest. The elevation shift the pump must make to transport water is known as the static head. You will just need to take the difference in elevation between the high point of the waterfall or filtration system and the level of the pond into account for this calculation. In this setting, each foot of rise corresponds to one foot of static head.
Second, you need to consult the flow chart that was provided by the manufacturer. For the total static head, take a look at the expected flow rate. Next, using the Friction Loss chart, use that amount to determine the Friction Head. For this calculation, you’ll need to know the pipe’s diameter and length. You will notice significant variations in this region depending on the pipe’s size. You’ll be able to achieve your maximum flow capacity by using a larger pipe.
To determine your TDH, add the Friction Head to the Static Head after you’ve computed it (be careful to include the elbows and other pipes as references on the table). Check the flow chart with your TDH in hand to see if it will deliver the flow needed for the application.
Are you still unsure about the solution or simply don’t want to attempt to find it yourself? The ideal waterfall pump for your needs can then be determined by consulting user evaluations or expert advice.