Horticulture Fact Sheet

The University of Georgia College of Agricultural and Environmental Sciences
Cooperative Extension Service

Water Gardens: Installation and Maintenance

(The following information was prepared by Steven Dobbs, former Extension Horticulturist at Oklahoma State University)

Necessary Supplies
Installing a Water Garden
Pool Styles
Ready, Set, Dig
Fountains and Waterfalls
Calculating Pond Capacity
Aquatic Plants
Pond Animal Life
Caring for the Water Garden
Sources

Water gardens are becoming one of the most popular do-it-yourself landscape projects. Homeowners appreciate the boost in property value, not to mention the relaxing atmosphere! Water gardens can be designed to fit virtually any existing landscape, no matter how large or small while providing years of enjoyment. Prices start around $150 and go up into the thousands.

Necessary Supplies

• Liner or prefabricated pool. A liner must be large enough to fit the excavation site and overlap the top edges. Figure liner size based on 2 X depth + 1 foot each direction.
• Pick, shovel, or back hoe; heavy rope or water hose; and stakes for excavation.
• One or two straight boards, framing square and/or level to make sure the side and top edges of the pool are even.
• Border materials (coping) such as stone or brick.
• Submersible pump, filter(s), and outlet.
• Builders sand, carpet padding or commercial underliner for lining base of pool.
• Assorted aquatic plants.
• Various fish.
• Water treatment, and fish care supplies.
• Fountain and/or waterfall and necessary attachments.
• Special lights are optional for illumination at night.

Installing a Water Garden

When choosing the location of a pond or pool, the gardener should consider placing it so that it can be viewed and appreciated through a window from the house or as a focal point in the landscape. Other factors to consider are:

Exposure to sunlight. Various water plants will need a spot with full sun, at least five hours, but preferably as much as eight hours a day. A shadier spot is fine, especially afternoon shade, but limits the choice of aquatic plants. An exception would be smaller ponds around 100 gallons of water which do better with afternoon shade.

Drainage. Soil in the site should be well drained. Boggy wet soil can distort the shape of an artificial pool and crack or break the liner. A pool placed in sandy or crumbly soil also has to be prepared to keep the sides or bottom from continuous shifting or settling. Additionally, avoid runoff areas of the landscape.

Proximity to trees. If the pond is directly under trees, leaves falling in the pond can decay, harming fish and plant life and clogging pumps and filters. Another consideration is damage to tree roots.

Accessibility to electricity and water. The pool will most likely be filled with tap water from a garden hose, and will occasionally need an adjustment in the water level during evaporation so an accessible water source is mandatory.

An electrical submergible pump is generally used to recirculate water for fountains and waterfalls and needs a normal household circuit plug (1 10 volts, 20 amps) and should be at the most 6 feet from the water garden. In many cases, it is wise to spend the extra money to invest in a sound fault interrupter to maintain any voltage fluctuations or shortages.

Special regulations. Some municipalities or housing divisions may have special ordinances that effect location, fencing, depth, etc. concerning such construction. Check with officials in your area for any such guidelines.

Size. In most cases a budget dictates the size of the pool or water garden. However, it is recommended that the pool depth be at least 18 - 24 inches deep, preferably deeper in colder climates. Additionally, aquatic plants and fish also acquire a better balance in competition with algae in deeper pools.

Pool Styles

There are several ways to create a water garden pool. The most popular way is by using a plastic liner which comes in PVC (polyvinyl chloride), Butl Rubber, or Polyethelene materials. These liners are chemically inert and safe for fish and plants. They come in various thicknesses anywhere from 20 - 45 mils and generally last anywhere from 10-20 years. Most liners will be the largest material expense with the price based on the size of your water garden and liner selection.

When shopping for liners, avoid pool prototypes that have been treated with an algicide inhibitor. These materials can be harmful to the plant and animal balance that naturally occurs in the pool. Furthermore, regular 2-6 mil black plastic sheeting is not well adapted for pool use.

Additional materials that can be used are prefabricated fiberglass pools which are considerably more expensive as well as concrete installed designs. Since adequate mixing and reinforcement is needed to avoid immediate cracking, hiring a professional is recommended for this option. Other pool designs have been made with livestock watering troughs submerged in the ground, or there are container kits available through various mail-order and full service retail garden center outlets.

Ready, Set, Dig

This is the most physical and time consuming step in the installation process. Whether installing a liner or prefabricated pool, the steps are similar.

1. Outline the pond shape with a heavy rope or water hose and stake at several locations to avoid movement during excavation. One can also spray paint the outline and move the hose or rope during excavation. If installing a prefab pool, place the pool on the ground and map the outline at least 2 inches wider in each direction.
2. Dig a hole to the exact shape adding two inches to the depth to accommodate a layer of sand. When digging for a liner pool, create a "shelf" area 9 - 12 inches along the perimeter to place container bog (marginal) plants. When digging for a prefab pool, follow the contours of the shell including built-in shelves. Clear the hole of rocks and other debris, smooth the soil and level the top edges to make sure the installed liner will be camouflaged. Place a 2-by-4 board over the top of the pool at various soil line locations and use a carpenter level on the board to detect the balance of the soil level and make any needed adjustments.
3. An optional step in some cases is to line the excavation with about two inches of damp sand to help prevent punctures, especially in rocky soils. Smooth it down with a 2-by-4. Carpet padding, or commercial liner underlay can also be used.
4. The liner will be more flexible and easier to work if allowed to warm in the sun prior to installation. Do not drag the liner across the ground to prevent any punctures. Also avoid laying the liner on turfgrass for a long period of time or heat scorch can occur to the lawn. Center the liner over the hole and push it outward into the corners. Avoid wearing shoes when walking on the liner during these steps for extra caution in avoiding puncturing of the liner. Fold the liner into pleats where it tends to bunch at curves or corners and anchor it with stones, bricks, etc. Cement or mortar can be used to stabilize the stones, however, this can take away from the natural appearance and potentially cause pH problems with the water. If the stones or bricks are not stabilized with mortar, observers can be at a safety risk if allowed to walk on these materials. Smooth out any additional folds and wrinkles in the liner as the pool fills with water. Shut the water off when it becomes level with the liner on all sides. If using prefab shells, it may take several times of lowering it to get the edges of the hole level. Once the shell is in place, fill the pond slowly. Backfill with soil as the water level rises to ensure that shell walls are adequately supported by soil.
5. Trim away the surplus liner, leaving at least 6 inches around the edge. Bury the edge with excess soil and cover with remaining stones, bricks, or other paving material. Don't forget to extend the coping material over the pool edge a few inches to further protect the liner from sun degradation.
6. Fill with water and dechlorinate if using treated water.

Fountains and Waterfalls

Fountains and waterfalls give the water garden a focal point in addition to adding beauty. Furthermore, place the focal structure in a location to get the greatest viewing impact

Fountains come in a wide range of shapes, colors, sizes, price ranges and are available at many related retail sources. A waterfall is generally created by building a slope using excess soil, liner material and assorted rocks to create a stream that is recycled with a submergible pump. Plastic tubing or a dark colored water hose is attached to lead from the pool pump up-and-under the waterfall during construction. It is especially important that the height of the waterfall or fountain spray coincide with the size of the water garden.

Calculating Pond Capacity

Aquatic Plants

Basically there are four types of plants you can stock your pool with; deep water plants, bog plants (marginals), oxygenators, and floating plants. A small mix of the plants ensures a thriving self-sustaining system. Cover 60-70 percent of the pond surface with floating plants like water hyacinth and/or container plants with floating foliage like water lilies. Submerged or oxygenating plants are generally stocked anywhere from 1-2 bunches per square yard of pond surface area depending on the size of the pond.

Many aquatic plants are very aggressive and as a result should be planted in containers to prevent spreading or overcrowding. Fill the containers with heavy garden soil and avoid chemicals or fertilizers, etc. that can harm aquatic life. Pack the soil tightly in the container leaving 1-2 inches from the container rim. Cover the remaining depth with pea gravel to keep the soil from floating up and lower the container to the correct depth in the pond.

Plants should be introduced to the pond during the growing season. In newly constructed pools it is also advised to station the plants several weeks prior to the introduction of the fish.

Tropical plants are not likely to overwinter and need to be taken into a greenhouse pond for protection and replanted when temperatures are at least 75 F degrees during the day and 65 degrees F at night. Most containerized aquatic plants will need to be divided and repotted every 3-4 years.

Fertilization can be done by using slow release tablets applied in the container at recommended rates for marginal/bog and deep water plants. Floating plants are generally fertilized with liquid or water soluble fertilizers specifically manufactured for aquatic plants. Follow label directions closely since overfertilization can encourage an increase in algae growth.

Pond Animal Life

It is crucial to wait 24-48 hours before stocking the pool to allow for the chlorine to evaporate. It is also advisable with chloramine or chlorine dioxide treated water to use counteractive chemicals from your water garden supplier. Various brands are available with many adding enzymes, aloe, and other ingredients to healthfully aid the fish during any transition period.

The combination of fish with the aquatic plants creates an ecological balance in the pond. In addition to a filter system, fish and aquatic plants should counteract any algae growth that occurs after construction. It can take anywhere from 6-8 weeks for this balance to succeed.

In general, aquarium, tropical fish or bait fish are not suited for pond life; however, there are many other assortments of fish that are well adapted.

Goldfish are very hardy and can survive even harsh winters by "hibernating" at the bottom of the pond. Shubunkin, Calicoes, Orandas, Fantails such as Chinese Moor, and Comets are popular types of goldfish. Golden Orfe, a popular large fish often found in colder climates do not adapt well to our hot summers. Japanese Koi are also very popular, especially in warmer climates. The colorful Koi can grow to two or three feet long over several years, thus needing larger and deeper pools. They also have been known to become quite aggressive on container plants with over-stocking practices.

When selecting fish, pick out colors and scale patterns that are appealing, but even more important is to choose fish adapted for your area that are healthy, active and alert.

Before releasing into the water garden, fish need to be acclimated to the water temperature by floating in a plastic bag on the surface for 15-20 minutes. Place newspaper over the plastic bag and splash with water to keep in place during this time for further heating from the sun. To keep a healthy balance in the water garden don't stock with more than 1-2 inches of fish for every square foot or 3-5 gallons of water. Larger fish are stocked at a rate of 1/2 inch per 3-5 gallons or square foot.

It's not necessary to feed fish in well-stocked ponds, because they can get their nutrition from plants and algae. However, most gardeners enjoy feeding their fish, but do so to a minimum, to avoid over growth and clouding of the water.

Caring for the Water Garden

As with any garden, maintenance is necessary to keep a water garden thriving. By fulfilling a few routine chores, a water garden can give long lasting beauty and enjoyment for years to come.

Algae and Other Debris

Immediately after installation, and again every spring, before surface plants limit the warming effect of sunlight on the water, algae flourish and cloud the water. The water will clear up once the other aquatic plants grow and the ecological balance is established. However, excess algae may periodically occur. To keep it to a minimum, avoid stirring up the bottom of the pond unnecessarily. If algicides are used, make sure they won't harm pond fish or plants and treat in the morning between 8-10 a.m. when oxygen is more prolific. Clean up any excess dead algae with a water vac to avoid adding nutrients to encourage new growth.

Installing a filtration system will also aid in keeping the water clear of algae and other debris. The filter should be cleaned at least once a week, or as needed.

Water Level

To protect the pool liner and keep plants healthy, maintain a water level that is even with the top of the pool. Furthermore, if the water level dips below pump intake, the pump's motor can burn out. In hot weather, water may have to be added to counteract evaporation. It's best to add a little every few days ( no more than 5% per day) rather than all at once, since this could shock fish and accelerate algae growth.

In new pools, it is also a good idea to have the pH tested to be sure it falls in a safe range of 6.8 to 8.5. A higher or more basic pH imparts the least amount of algae problems. Additional water tests are optional unless fish and the general balance of the pond becomes disrupted. At that time, test for nitrites, ammonia, hardness, pH, and carbonates to mention a few.

Leaks, Bugs and Other Pests

Leaks are not common but can occur in liners and fiberglass shells. There are patch kits available from suppliers that easily correct this dilemma. Wait for the water level to stop dropping to determine where the leak is and eradicate any causes (sharp objects) before repairing.

If the pond seems to generate mosquitos, install a waterfall or fountain to circulate the water, or better yet, stock the pool with fish. Bacillus thutingiensis (Bt) var. israelensis can also be used in the pond by following directions for mosquito larvae control.

To rid pond plants of pest, don't use just any insecticides, especially in the pond. It is better to remove the plant for treatment. Floating plants can be moved to another holding tank without fish for appropriate control which may include removing one leaf or part of the infected plant. Assorted caterpillars and aphids are the primary pest problem. Bacillus thuringiensis (Bt) var. kurstaki is suggested for caterpillar problems. Check with a full service garden center or your County Extension office for additional labeled controls.

Winterizing

Use a hand held skimming device to remove fallen leaves from the pool to avoid clogging of the pump and disturbing the oxygen balance. When leaf drop is heaviest in the fall, cover the pool with a screen or net. Ponds in colder climates need to be "closed" for the winter. Simply remove the filter after the first frost and leave the pond alone until the onset of spring and the water temperatures reach 45-50 degrees F. Under the coldest of circumstances, there are even pump protectors on the market that can be installed during the winter months.

When the foliage turns brown on the marginal aquatics, reduce them by two-thirds of their height to prevent debris accumulation and breeding grounds for pests. Do not prune any new foliage growth that is initiated during the winter. Also, stop any fertilization practices during the winter months. Move hardy water lilies and other hardy aquatic container plants to the deepest section of the pond. Hardy plants should survive as long as the water does not freeze solid to the rootstock. Under the coldest of circumstances, a submergible heater can be installed.

The fancier fish should be moved to an indoor cold-water aquarium; however, most can be left in the pool year round as long as ice doesn't cover the entire surface for more than a week or two. Trapped gases may be harmful to fish under these circumstances. In this case, keep an area free of ice when it forms. Do not crack or break ice. The shock waves can injure your fish. If you have no mechanical way of keeping the ice from forming, consider using a pool heater or warming device with a thermostat. Overheating the water temperature can cause difficulty and even death to both fish and plants. Another option is to cover the pond with canvas or greenhouse plastic on a frame 6 inches up from the water. Feed your fish extra food, if they will eat it, from the time the temperature begins to cool down until the water temperature drops below 45 degrees F. Fish don't need to be fed during the winter because their metabolism virtually shuts down in water temperatures below 50 degrees. Feeding during the winter is okay if fish activity occurs during warm conditions.

In the spring, reinstall the filter, begin feeding the fish, and replant if necessary.

Cleaning Tips

Weekly cleanings to remove leaves, dead aquatic plant foliage, etc., are recommended. A skimming net is essential and more expensive equipment such as a pool, spa, or water vacuum is optional. Gardeners who want to do a real thorough cleaning can rent a submersible pump and drain the pool. Such cleaning is often recommended every four to five years; however, some water garden suppliers don't recommend completely draining the pool since it disrupts the established ecological balance. If a cleaning is absolutely needed, before all the water is drained from the pond, fish should be placed in the shade in a tub of water the same temperature as that in the pool (preferably original pool water). If the fish are to be out of the pool for several hours it is best to provide aeration. The same should be done with submerged and floating plants. Other container plants can sit covered in the shade for a short while. The pool or liner should be cleaned with a very soft bristled brush. Do not remove the beneficial algae which grow on the sides of the pool. Detergents are unnecessary and can leave residues that are harmful to the animal and plant life. Clean the filter and associated attachments. Any time large quantities of treated tap water is added or replaced, it needs to be retreated with recommended chemicals to eliminate chlorine. Plant and fish can be reintroduced to the pond when the water temperature reaches its pre-cleaning level. Now is also a good time to divide and replant aquatic plants if necessary.

Water Efficiency

Aquatic Plants - All plants transpire moisture, some more than others. As a general rule, taller plants with more leaves release more moisture than low growing plants under 12 inches in height. Plants such as water lilies, water hawthome, pennywort, water cress, and duckweed are considered water saving.

Timers - For additional conservation of water and electricity, it has been suggested to put a timer on your water features such as waterfalls and fountains during off use hours. However, our hot and humid conditions usually require constant water circulation and splashing to keep the oxygen levels safe for both plants and fish. It is unlikely that the water gardening enthusiast will notice any or little increase in electric usage from the pumps regardless.

Wind Blocks - Landscape plantings bordering the pool or walls can reduce evaporation. Some companies even have wind sensors that shut off water features during extremely windy periods. Again use caution when shutting off water circulation during hot weather.

Treating Sick Fish

Almost all fish diseases show up within 15-20 days after they have been handled from cleaning pools, adding new fish, etc. When fish are weak or injured, they are more susceptible to contact parasites or fungi. Some symptoms are tail rot, white spots or growths and general inactiveness. Contact your water garden supplier for any necessary treatment.

Sources

Many full service retail garden centers are merchandising great selections of water garden materials. You can also write to the following suppliers and/or contacts for water gardening tools, fish and plants, if you do not have a source in your area.

The Cooperative Extension Service does not endorse any of the companies, books, or products referred to herein. Names given represent commonly available sources for these types of products.

An Equal Opportunity Employer/Affirmative Action Organization Committed to a Diverse Work Force

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, The University of Georgia College of Agricultural and Environmental Sciences and the U.S. Department of Agriculture cooperating.

Gale A. Buchanan, Dean and Director