How To Choose The Correct Pond Pump

Choosing a pump for your pond or fountain is a crucial step to ensure you maintain proper water movement. Failure to keep the water adequately circulated can result in stagnation, algae buildup, and mosquitoes. In addition, if you have fish, plants, or other aquatic life in your pond, you must keep the water healthy by evenly distributing the oxygen levels and other nutrients.

Aquascape AquaJet® Pond Pumps

Types of Pond Water Pumps

There are two main types of pond water pumps: submersible and external (out-of-pond), also known as centrifugal pumps. Depending on the application, each pump offers specific advantages.

Aquascape AquaForce® Solids-Handling Pond Pumps

Submersible Pond Pumps

Submersible pumps are designed to be fully submerged underwater at the deepest part of the pond. They are placed directly into your pond or in a skimmer box or pond vault. Submersible pumps range in size from 50 to 5,000 gallons per hour. They are easy to install and are sometimes a more economical solution for smaller ponds (up to 1000 gallons of water). They are also quiet and can also be used to drain your pond. If you have fish or other aquatic life in your pond, you may want to consider a model that does not use oil because there is a danger of the pump seal breaking and oil coolant leaking into the water.

Aquascape AquaForce® 4000-8000 Adjustable Flow Solids-Handling Pond Pump

Centrifugal Pond Pumps

External or centrifugal pond pumps are a reliable, energy-efficient option. They are installed in a dry location near your pond. External pond water pumps are suitable for larger ponds (over 1000 gallons). Compared to a submersible pump, they are typically louder and more complicated to install; however, they are easier to maintain.

When selecting a pond pump, it’s essential to keep in mind that pumps have different cord lengths. Ensure the cord is long enough to go through the pond and plugin far away from the water. Some electrical codes specify that the outlet for water features must be at least 6 feet away from the water. Therefore, it is recommended that you avoid using an extension cord. However, if you must use one, make sure it’s suitable for outdoor use and plugged into a ground fault circuit interrupter (GFCI) so that it will immediately shut off if there is an overload.

How to Size a Fountain or Pond Pump

Pond pumps are sized by gallons per hour (GPH) at one foot of lift or height. Larger capacity pumps are rated by horsepower (HP). To determine the size pond pump, first, you need to calculate the volume of water in the pond. To calculate the volume of water in gallons, multiply the length x width x average depth x 7.5.

outdoor water garden pond

Water Circulation Factors

It is recommended that pond water is circulated at least once per hour. For example, if you have a 500-gallon pond, you need a pump that runs 500 gallons per hour at the discharge height. If your pond has a pressurized filter, you ideally want to turn the water approximately once every two hours. For example, if you have a 1000 gallon pond, you need a pond pump rated at a minimum of 500 GPH. If your pond has a skimmer or waterfall, the water should be turned approximately once every hour. Therefore, if you have an 1800 gallon pond, you will need an 1800 GPH rated pump.

family in water garden

Calculating Head and Lift Height

Two of the most critical measurements in sizing a pond or fountain pump are the maximum head height rating and maximum lift. Head height means the vertical height the pump raises water above the surface of the pond. The pond fountain pump’s top height can lift the water to is called “Maximum Head” or “Max Head.” The “Head” is measured straight up from the water level of the pond. Its length then measures any horizontal/diagonal flow, and 1’ of “Head” added per 10’ of horizontal/diagonal distance. To calculate the lift, you need to measure how far the water in your fountain has to travel from the pump’s location in your rush to the top of the fountain where the water comes out. Then you need to select a pump that lifts higher than that measurement. For example, if that distance is 24”, than you will need a fountain pump that lifts at least 36” tall. The “maximum lift” is the maximum height that the pump will raise the water.

Medium 16ft Pondless Waterfall_04

Selecting the Proper Pond Water Pump Tubing

It is also essential to use the correct tubing size because it directly affects the pond pump’s maximum lift capability. If you use smaller tubing than specified, you will limit the pump’s maximum lift and the amount of water circulated.

Choosing the right pond water pump for your pond or fountain requires careful consideration and a little upfront research. However, doing so will go a long way toward keeping your water clean and healthy and your pump operating efficiently.

Learning How To Build A Water Garden In Your backyard

Build your pond and waterfall, then stock it with plants and fish. Learn the basic techniques for creating a relaxing water feature in your backyard.


Constructing the sides

Take the time to arrange the rocks in pleasing combinations.

Something is soothing about the scent, sound, and sight of water, which washes away stress and strain. So while you can’t stop by the French Riviera or Walden Pond after a hectic day of work, you can have a private oasis waiting for you at home, complete with gurgling water and colorful fish.

In this story, we’ll walk you through the basic steps for building one of our favorite water garden ideas, a backyard pond. Roll up your sleeves—it’s mostly muscle work. There’s no need for precise measurements, no unforgiving blueprint to follow, and no deadlines. Working like beavers, you and anyone else with a strong back could probably finish a large pond in a couple of weekends. But that would take the fun out of it. Please give yourself plenty of time, and creating a pond will be almost as relaxing as sitting beside it.

The primary pond consists of a good-quality liner, a high-efficiency pump, and lots of stone and gravel. For a little bit more money, you can add the convenience of a filtration system, which will reduce your weekly maintenance chores. Larger ponds won’t cost a whole lot more; you’ve already made most of your investment in pumps and filters. We’ll show you how to build a pond waterfall with rocks here:

With water garden ideas, careful planning prevents trouble later on.

Layout the pond with a hose

Use a garden hose to establish approximate pond borders, adjusting and readjusting until you’re satisfied with the shape of the pond. Then dig out the pond bed, terracing both shallow and deeper areas for plants. Exposed rocks, tree roots, and anything else that might puncture the liner must be removed from the hole.

Digging out a pond hole is grunt work, not an intellectual endeavor. Still, it requires some planning. So before you grab your shovel, roughly map out the shape, desired plant shelves (Photo 2), and the pump and waterfall locations. Here are some more key considerations:

  • Select a location where you can readily enjoy your pond, close to a patio or visible from a window. Don’t stick your pond in the back corner of your yard where only the squirrels will enjoy it.
  • You can locate your pond in almost any area of your yard as long as it doesn’t receive runoff from rainfall. You don’t want lawn and garden chemicals washing into your pond. As a rule, the more sun, the better, but don’t discount a shadier spot. Just stay away from the area inside the canopy of your trees, the “drip line.” If you locate your pond near trees, be prepared to clean leaves from the pond more often. Most water plants prefer the sun, but some can survive in the shade. Choose hardier plants and fertilize more often if you select a shaded site.
  • A toddler can drown in the smallest pond, so some building codes require fences around ponds 18 in. deep and deeper. Call your local Department of Inspections, explain that you’re building a water garden (not a swimming pool) and ask what rules apply. But if you have young kids, consider installing a fence around it anyway. Be sure to choose a fence that cannot be climbed.
  • Caution: Before you dig, call your utility company or 811 and ask someone to come out and mark your property for buried utilities. Utility companies usually won’t draw “private” lines, that is, lines added for conveniences, such as a power line from a house to the garage or a gas line to an outdoor grill. Turn off the power or gas to these areas if you suspect a line is in the vicinity of your digging.
  • Oversize your pond if possible. Once you stock it with fish and plants, you’ll be surprised how much smaller it’ll look. Besides, a large pond is often easier to take care of than a small one. (Controlling algae is often more manageable with a large pond.) The additional expense is minimal. A 10 x 16-ft. size is a good starting point.
  • Water circulation is essential, so position the pump as far as possible from the water inlet (waterfall, stream, or fountain).
  • Digging even a small pond is a big job. Plan plenty of breaks or enlist the neighborhood teenagers to help you out for a day.
  • To power the pump, you’ll need an outdoor electrical outlet (Fig. A). Have a licensed electrician install a GFCI-protected outlet if you’re not comfortable with wiring.

How to build a pond waterfall with rocks: Pond-building tips

  1. Use the excavated dirt to berm up round your pond or build up your waterfall area. It will save you the hassle of having it hauled away or running it around your yard in a wheelbarrow.
  2. Before you start digging, lay on the ground the water circulation pipe that goes from the pump to the waterfall. Throw the excavated soil on top of it. This will save you the work of digging a trench to bury the pipe.
  3. Use a tablet-style fertilizer pressed into the soil around your nearby landscape plantings, so the nutrients don’t leach into the water.

Choose a flexible liner.

Line the hole

Line the pond bed with a 1/2-in. layer of newspapers. The newspaper helps prevent liner punctures and will eventually decompose and form a clay-like layer. You can also use the special pond underlayment that’s available at your pond supply dealer.

We’re using a flexible liner made of a synthetic rubber called EPDM (ethylene propylene diene monomer). The liner is economical, durable, and easy to install. You can create almost any shape, and it adapts well to most site conditions.

Flexible plastic liners are also available. They’re made of PVC (polyvinyl chloride) and HDPE (high-density polyethylenes). These liners aren’t as flexible as rubber liners. Plastic liners are often used on large holding ponds when the economy is a concern and flexibility is not. The preformed liners found at many home and garden centers are less desirable. These are essentially large plastic or fiberglass tubs. At first glance, these seem easier to install, but this usually isn’t the case. Preformed liners can be difficult to handle and level and, when lined with rocks and boulders, aren’t as forgiving as flexible ones.

Guidelines for purchasing a liner

  • Most professionals use a 45-mil EPDM liner. (A mil is a thousandth of an inch.) It’s strong yet flexible enough to handle easily (Photo 5).
  • If you plan to have fish, make sure your liner is stamped “fish-safe. ” Roofers often use a type of EPDM that’s been treated with chemicals that can harm fish.
  • Purchase your liner in one single sheet, large enough to cover the entire pond bottom and sides. Liners are commonly cut and sold from 100-ft. rolls with 10- to 20-ft. widths; you can custom-order liners up to 45 ft. wide. Liners can be spliced if necessary, but it involves more work and provides an opportunity for a leak. If your waterfall or stream requires extra length, use a separate piece of liner. You don’t need to glue the two liners together as long as the stream or waterfall liner is higher than the pond’s water level.
  • Calculate the dimensions of the liner by measuring the maximum length and the maximum width of your pond, then add three times the depth measurement to each dimension. Better a bit big than a bit small.

Pond Features

This basic pond layout, with sloping, stair-stepped sides and a pump and waterfall at opposite ends, can be adapted to larger or smaller ponds.

Make your pond hospitable to plants and fish!

Pond dweller

Plants and fish work together to keep the pond ecosystem healthy

A pond is just a hole filled with water. Add plants, and it becomes a water garden. Add fish, and your pond comes alive. You’ve got an entire aquatic ecosystem right in your backyard. Here are a few things to keep in mind when planning for plants and fish.

  • Before adding plants or fish to your newly filled pond, wait a week for the chemicals in the tap water to neutralize. To accelerate the process, you can add a dechlorinator to the water. Consult your water garden supplier for more info on this chemical.
  • Anchor plants in pots or baskets designed for aquatic plants. A third option is to place the roots of each plant in “root balls,” a mix of gravel and soil in nylon stockings tied with soldering wire (Fig. A). Rootballs are cheaper than pots or baskets and are easier to move. They also keep fish from disturbing the soil. Mistake: Don’t use standard potting soil in your pond. The high nutrient content encourages algae growth. Ordinary garden soil is just fine.
  • If you plan to stock your pond with fish, part of it must be at least 18 in. deep.
  • If you plan to leave your fish in year-round, keep a spot open in the pond by running an aerator or fountain all winter. If your climate is so cold that the pond still freezes, purchase a floating heater. Keeping your pond open provides needed oxygen for the fish and allows gases to escape.
  • For convenience, leave hardy water plants in all winter. Bring tropicals or water plants from warmer plant zones inside for the winter.
  • Fish, like teenagers, need their space. One inch of fish for every square foot of pond surface is a good rule of thumb. For example, a 4-in. fish needs 4 sq. ft. of pond surface.
  • Hardy fish—goldfish, for example— don’t require much attention. You don’t even need to feed them once they’re established, as long as your pond isn’t overstocked. Hardy ones can survive by eating insects and the plant life in your pond. They help keep your pond clean. If you plan to stock your pond with more exotic species, you’ll have to do more to ensure their survival. Look in a library or bookstore for books about tropical fish, home aquariums, and fish ponds.

Keep your pond healthy—make a waterfall.

water garden pond pump

It’s essential for water to circulate and aerate throughout the pond. Buying an inexpensive fountainhead and connecting it to the end of the water circulation pipe is the easiest way to accomplish this.

The most dramatic way to circulate and aerate water in your pond is to construct a waterfall and stream. Install a stream bed liner the same way as for your pond. Begin by digging a holding pool. The pool keeps water from spraying out of the circulation pipe and allows it to spill lazily into the pond. Next, dig the course for the water to flow in. Two feet wide is a suitable dimension. Finally, lay the liner in place, overlapping the pond liner by at least 6 in.

Creating an attractive water flow will take some trial-and-error adjustments of the rocks. But this is the fun part. First, don’t mortar your rocks in place. The mortar looks unnatural and makes it challenging to move rocks around to get the desired effect.

To control water’s frustrating tendency to flow invisibly under or between rocks instead of pleasantly over them, fill hidden passages with expanding foam sealant. It’s available at hardware stores. Pond suppliers also sell a special black-colored expanding foam that becomes almost invisible.

Choosing the correct water pump.

Buy a pump that’ll turn over the pond’s entire volume once per hour. To size your pump, calculate the approximate volume in your pond: Multiply the length (ft.) x the width (ft.) x the average depth (ft.) and multiply by the conversion factor of 7.48. Also, note the pump’s height and distance to move the water between the pump and the water inlet. With these figures in hand, consult your pump supplier for the pump size and circulation pipe diameter for your pond.

Once you’ve determined the pump size, decide whether to buy a high- or low-efficiency pump. High-efficiency pumps cost more but last longer and are less expensive to run. Since your pond pump will run 24 hours a day, seven days a week, the lower utility bills will soon make up for the higher price tag.

Place your pump in a pump container to keep it from clogging with leaves or debris. Either buy one from your pond dealer, install the pump in a skimmer container, or make one from a sturdy garbage can be peppered with 1/4-in. holes (Photo 6). Don’t be shy about drilling holes. The more water you allow through the can, the better.

pond pumps people water

Simplify Maintenance with a Skimmer and Filter!

Keeping your pond clean isn’t difficult; once you get it down, it’ll be as routine as taking a bath. Your pond has two sources of pollution: debris that falls or blows into the water and algae. Pick up leaves and other windblown debris with a fine-mesh net. The type used for skimming swimming pools works excellent. Skim daily to prevent the material from sinking to the bottom, decomposing, and creating sludge.

An easier but more expensive way to clean out this debris is with an automatic skimmer system, kind of a dishwasher for your pond. Once you have one, you can’t imagine pond life without it. A skimmer system works off the inflow of your pump. Water is drawn through a tube containing a mesh bag that collects leaves, paper, and other debris. The system bags it for you—all you have to do is empty the bag about once a week. The frequency will depend on the time of year, the amount of wind, and the number of trees in your area. It’s easiest to install a skimmer system when you build your pond. If you decide to add it later, you’ll have to drain your pond, dig a hole and readjust the liner.

The second threat to a clean pond is algae, microscopic plants that’ll turn your pond green. A small amount of algae is beneficial, but large amounts can have your pond looking like a swamp.

Keep algae at bay by limiting nutrients and sunlight. Here are some tips for doing this:

  • Shade the surface of the pond with water plants such as lilies. A good rule of thumb is to cover one-third of the surface with plants.
  • Install a variety of plants. Plants consume nutrients from fish waste and decomposing matter in your pond, stealing the food algae need to live.
  • Keep debris out of the water. As waste decomposes, it releases nutrients into the water.
  • Don’t overstock your pond with fish. Too many fish will release more nutrients than the plants and bacteria can consume, leaving food for algae.
  • Don’t overfeed your fish. Food not consumed by the fish provides nutrients for algae.
  • As a further measure, biological and mechanical filters are available from your pond supplier. They take a lot of guesswork out of keeping a balanced, clean, and clear pond.

Once you establish a biological balance in your pond, maintenance is minimal. A thorough annual cleaning (draining and rinsing out the pond) and periodic maintenance (keeping debris out) are all that’s required.

Have a question? Ready to install? Contact us!

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