Pond Installation FAQ

How do I get started on building a pond?

First, decide on the location: near patio, deck, porch, near a window, etc. Try to place in a sunny location if possible, but the most important factor is put the pond where it can be enjoyed, even if it means less than an ideal six to eight hours a day of sunlight. Next, decide on the size of the pond. To help you visualize the pond, lay a string on the ground to establish a shape you like. You may choose a pre-formed pond that is rigid or a liner that is flexible.


Should I build my water garden large or small?

Although your budget and available space will determine the size, the water garden should fit the scale of the landscape. Many people build small, then expand after they discover the fun saying, "I wish I had built this larger!" Often, people will add a second or third pond when they realize it is easy to add another pond to an existing system.


What is a large water garden?

A large water garden is usually regarded as one that is 1500 gallons or more. This can be compared to a body of water that is 10' x 13' x 19" deep.


What is considered a small water garden?

A small water garden is one that is less than 1500 gallons of water, or less than 10'x 13'x 19" deep. It could even be a small patio pond that holds 50 gallons of water and is 18 inches deep. Many "starter" ponds are 200-500 gallons. Small ponds are easily expanded by adding a second pond connected by a waterfall or by digging the original pond larger.

Should I make my water garden with a liner or a preformed pond?

Most people choose the flexibility of a liner because they can build a pond any size, shape and depth. The life of the liner material is comparable to the best rigid fiberglass ponds and the cost is much less than the rigid fiberglass. The standard 45 mil EPDM is the liner of choice since it is durable and available in many sizes. It is a great choice for most water gardens. Rigid, pre-formed ponds are a good choice for a beginner. The sizes and shapes are limited to what is available in the store. The best place for a pre-formed pond is an aboveground water garden where soil must be built up around it. Many gardeners prefer to start a waterfall with a pre-formed header or spillway pond. This gives a controlled, rigid starting point for the falls.

If I choose a preformed pond, should I use a fiberglass or a plastic pond?

The highest quality pre-formed pond is made of fiberglass. It is the strongest material in rigid pre-forms, especially for raised water gardens where soil must be built up around the pond where self-support is essential. The cost is higher for this type of material when contrasted with plastic. Plastic ponds, while more economical, do not offer the support for freestanding use. It is difficult to build up around a plastic pond and support the shape evenly. Where support is not uniform, there is a risk of cracking of the plastic form. Many people start with a low cost plastic pond before deciding to upgrade to a rubber liner.

If I choose a flexible liner, should I use a rubber or PVC liner?

We prefer a rubber EPDM 45-mil liner as the membrane of choice for water gardening. The flexibility of the material in a wide range of temperatures makes rubber superior to PVC liners that get stiff in cold weather. Additionally, rubber liners are more resistant to material breakdown due to sunlight exposure, whereas PVC becomes brittle in a few years. Rubber liners are available in many pre-cut sizes as well as custom-cut sizes. PVC is more affordable however.

Do I need concrete for my stonework?

Where possible, avoid concrete or other masonry based products for any stonework in and around the water garden. For more formal ponds, concrete may be a good choice for the edging, but it is not necessary for a natural water garden. With good stone installation practices, the rock edge can be sturdy and strong. Concrete must be cured and then etched to reduce alkalinity by washing with muriatic acid. The alkaline nature of fresh concrete can cause numerous problems including water quality issues, especially pH imbalances. An incorrect pH will cause excessive algae, high ammonia and nitrite levels, and poor beneficial bacteria population growth which could result in odors, and general fish health troubles.

Should I use concrete in my waterfall construction?

Concrete in a waterfall causes the same pH concerns as using concrete in the stonework. See the topic above for this discussion. Another problem with using concrete in a waterfall is the falls must be built without the water running. This means the actual appearance of the falls is unknown until after the concrete has set up and cannot be changed. It is recommended that the falls be built with the method described under Waterfall Construction, using no concrete and while the water is flowing.

How deep should my pond be?

The average water garden in the temperate portion of the United States will rarely experience air temperatures below minus 20 degrees Fahrenheit nor exceed much above 110 degrees. This range of temperatures means the water garden must be 18-24 inches deep if the pond will contain goldfish and water plants. A depth deeper than this is not necessary to overwinter plants or fish. Water lilies will grow where the water is at least ten inches over the soil surface. They prefer depths of ten to twenty inches of water above the soil. Some varieties will tolerate much deeper water, but this is impractical in most water gardens. The choice of bog plants will determine how deep they are planted. Refer to specific plant charts to find exact depth requirements. Deeper water is needed for large fish like koi because they need more constant temperatures than are found in shallow water. Ponds with koi need water to be at least three feet deep for optimum water conditions.

Do I put my pond in the sun or shade?

Locate the pond where it can be enjoyed the most, even if it means sacrificing some sun exposure. This means choosing the location with the highest visibility, such as near a patio, porch, deck, kitchen or living room window. If a water garden can be positioned in at least six hours of direct sunlight it will produce more and better flowers. This would be the ideal location. There are many plants that can be planted in and around a water garden that tolerate shade. If the most visible location is shady, consider locating it in this place anyway and planting shade plants instead of moving the pond to a far away location that is sunny. Remember that the sun is for the plants to bloom best, not necessarily for the pond. The plants give shade to the water below, acting as a cooling mechanism. If the shade comes from the trees above, the result is the same for the water quality.

Should I put my water garden in the low part of my landscape?

While it may look like a logical place for a pond, the water garden should not be positioned in the lowest part of the landscape or in direct drainage patterns. This avoids water under the liner that could destroy the shape of the pond by undermining the soil. Water under the liner will cause the liner to billow up in the pond and upset potted plants. If there is a high water table, drainage tiles or other provisions should be considered, to prevent the possibility of water under the liner from occurring.

How do I build a waterfall on flat ground?

A waterfall on flat ground is best made with a preformed spillway or header pond. This is a rigid pond with a spillway constructed into the rim that allows the beginning of the waterfall to be built with complete control of the direction of the flow of the water. The soil that is built up around the sides of a waterfall and around the header pond tends to settle with time so a rigid pond eliminates the risk of the water flowing out in the wrong direction.

How do I build a waterfall on my hillside?

A waterfall should be proportionate to the surroundings and the pond to which it flows. Whether it meanders or flows straight into the pond depends upon the design.

Can I build a pond in the winter?

A water garden can be built anytime the ground is suitable for digging. If the ground is wet or frozen, avoid beginning a project until the soil is workable.

Should I line the bottom of my water garden with rocks?

Rocks on the bottom of a water garden will hide the liner but will make cleaning of the pond a difficult task. With proper care in maintaining the garden, a smooth liner bottom is easier in the long run. Cleaning around the bottom stonework is messy and time consuming, a tough job for the homeowner. From a safety standpoint, walking around on the rocky bottom that is covered with algae is treacherous. The pond must be walked in to prune and fertilize lilies if the water garden is large enough.

Should I use a skimmer for my pump?

For ponds over 1000 gallons, a skimmer is a very useful addition to the water garden. It can be incorporated into smaller ponds but may take up more room than is desired. The surface of the pond is vacuumed by the suction created by the pump inside the skimmer box. This a great way to keep the surface sparkling clean of debris like pollen, leaves and grass clippings. This material is collected inside the skimmer in a net before it settles to the bottom of the pond. Access to the pump is also easier since the pump is not at the bottom of a pond.

Should I build shelves in my liner pond for potted plants or plant into the stonework on the edge of my water garden?

Shelves are often built right into the edge of a pond to support potted plants. They should measure a minimum of ten inches wide and be eight inches under the water. They can be larger to accommodate larger pots or deeper for plants that require greater depths. If shelves are to be used, they are best placed at the backside of the water garden or to the sides, but not in the foreground. Unless very short plants are planted along the front, the view of the pond will be obstructed by front edge plantings. Consider building into the stonework planting areas that are incorporated as part of the transition from the landscape to the water. Some bare root plants can be inserted into gaps between stones where they will root in and thrive. Larger planting areas may be established by filling soil into larger openings within the stonework. This planting method gives a very natural appearance to the pond's edge, eliminating the view of a round pot sitting on a shelf.

What do I put under my liner to pad it when I build my pond?

There is a product called underlayment that is used for padding under the rubber liner. This heavy fabric protects the liner from puncture during installation. An alternative is to use underlayment as padding just for the sides and a layer of sand on the bottom of the pond. The layer of sand needs to be about two inches deep for adequate protection.

Can I build an above ground pond on my patio?

An above ground pond is easier for some people to take care of, eliminating excessive bending over during maintenance. This method of construction is often regarded as a safer alternative to an in-ground water garden where small children are involved. A raised pond is also easier to look down into. In extreme climates, the raised pond must have a heater floating on the surface to ensure survival of the fish and plants. In zone 7 or colder, a small patio pond may freeze enough to kill living plants and fish, but in warmer climates, heating is not necessary. A short or light freeze will not cause enough ice to harm anything.


Can I repair a cracked concrete pond successfully?

A concrete pond repair can be challenging, especially in cold climates where winter temperature extremes cause the ground to heave. Masonry based repair materials dry rigidly and will often break again during the winter. Aquata-poxy is a two-part, solvent free, 100% solids corrosion resistant epoxy coating for covering cement block, brick and cracked concrete ponds. When applied according to instructions, the result provides a long lasting repair.

Can I coat a wooden planter to make it hold water?

Wooden planters can be coated using Aquata-poxy to make them watertight.

How can I get water through the side of a pre-formed pond instead of going over the top edge?

Watertight fittings, called bulkhead fittings are used to go through a rigid pond like fiberglass or plastic. The fitting is inserted through a pre-drilled hole with gasket placed on both sides of the pond wall. The fitting is held in place by tightening a large nut that compresses the gaskets to make a tight fit. Rigid PVC pipe or tubing can be fitted to the bulkhead to carry water through the wall of the pond.


Do I need to use a ground fault circuit interrupter for my outdoor electrical needs?

A ground fault circuit interrupter (GFCI) must protect an outdoor receptacle. This mechanism prevents electrical shock in the event of a failure of an electrical system. This life-saving device is installed in place of an outlet or it can be manufactured into an extension cord (however, an extension cord should not be plugged into an outlet GFCI).

How can I prevent water from siphoning out of my upper pond when the power is off to the pump?

In the event of a power outage, water can be siphoned from an upper pond to a lower pond through the pump and tubing that powers the waterfall. The water can be prevented from being lost with an anti-siphon device called an In-Line Spring Check Valve. This spring activated fitting automatically plugs the water line when electrical power is lost, holding water in place until power is restored.

Can my waterfall be a biological filter?

The waterfall acts as one of the best, most efficient biological filters because it has a tremendous amount of wet surface area that harbors beneficial bacteria. With constant water flow over these irregular surfaces, bacteria thrive and process organic pollutants out of the water. Particles of soil and organic debris that are suspended in the water settle out as the water flows over the falls. The water is also cooled and oxygenated as it moves over the stone surfaces. These are the essential components of manufactured bio-filters, just in a natural form.