When planning a water garden, the first step is to decide which aspects of a pond you want to emphasize. For instance, if your primary interest is a koi pond, you must have a depth of at least three feet, preferably deeper, to accommodate these large ornamental fish. Koi ponds also require more sophisticated filtration. For goldfish, a depth of 18 – 24 inches is sufficient in areas with a moderate climate, such as
Once you have decided the type of pond you want to build, your water garden site should be chosen. Keep in mind that most people enjoy being able to view their garden from the comfort of their home, especially in inclement weather. The pond should be situated away from rain run-off, which can carry fertilizers, chemicals, and organic debris into the pond. These contribute to algae and can be toxic to fish.
The next step is deciding the type of material to use to line the pond. When considering a liner, there are several options, but the flexible 45 mil, fish grade, EPDM liner is the most practical. We have such confidence in this material that this is the only liner we sell or use in ponds we install.
NOTE: Roofing rubber should not be used, as it can be toxic to fish.
Digging The Pond
1. Outline the shape of the pond using a hose, rope or turf marking spray.
2. Excavate the basic shape, allowing for bog shelf, if desired, which should be
3. Choose the point which will be the surface level (remember that the pond should be higher than the surrounding area to prevent runoff). Use a straight 2x4 and builder’s level or strings and string level to assure precision.
4. Dig coping shelf about ½ the thickness of your coping and approximately 6″ wide depending on your choice of coping.
5. Line the excavation with protective underlay.
6. Place the liner in the pond.
7. Take off shoes and get in the pond and smooth the liner. Place some rocks around perimeter of the pond to secure the liner.
8. Start filling the pond with water, pulling wrinkles out as it fills. Some folding may be necessary in tight curves.
9. Arrange the coping material around the edge of the pond so that it extends over the liner.
Pond Water Quality
When we think of water quality we usually think of two things: the water’s ability to support aquatic life and clarity. Clarity is usually not a problem for aquatic life, but limits our ability to see and enjoy our fish. The pond owner should be concerned with both of these aspects.
While it is true that you can keep fish in an ornamental pond with no filtration, it severely limits the number of fish you can keep. In the wild, fish have large amounts of water so that toxins from their waste do not build up to dangerous levels. Most hobbyists will want to keep more fish than their ponds will naturally support. Fish excrete waste into the water in the form of ammonia, primarily through their gills. Also adding to the problem are organic compounds from fish feces, plant matter and soil which may flow into the pond.
In order to provide good water quality some form of waste removal must be provided. The methods used in the average ornamental ponds are mechanical filtration, and biological filtration. Mechanical filters physically remove solids from the pond by trapping the debris in some form of mat, brush, or sponge. Sumps or vortex chambers are also used to remove solids before going to the biological filter. Mechanical filters are effective but generally require frequent cleaning to remove the accumulated matter. Biological filtration is the most effective method of removing toxins from a pond by breaking down ammonia into nitrite and then into nitrate. This is accomplished using naturally occurring bacteria called nitrosomonas and nitrobacter, this is also how ammonia is broken down in natural bodies of water, but we must greatly improve on Mother Nature because of our limited space in the pond. We do this by providing a place for the bacteria to live and thrive. In a biological filter this place is a material on which the bacteria is exposed to large quantities of food and oxygen. The best material for accomplishing this is a synthetic matting material which offers a large surface area for the bacteria to colonize and also a large void area to allow large amounts of water to flow through carrying food for the bacteria. If the matting is too dense it will clog and not allow the water to flow through. We can also increase the efficiency by adding concentrated solutions of bacteria and enzymes and providing an abundant supply of oxygen to the bacteria by the use of air stones or aeration towers which mix large amounts of air with the water. There are also other organisms which colonize in a biological filter and help break down organic compounds.
A biological filter must run continuously during the season and not be shut down for more than a few hours as it will begin to die. A biological filter should be cleaned using dechlorinated water to avoid removing or killing the beneficial bacteria. Also the filter should not be over cleaned, rinse the media only enough to allow good flow through the filter. The brown stain on the filter media is the living bacteria.
The nitrates, which result after the breakdown of ammonia and nitrites, are food for the plants or food for the algae if plants are not available. If you keep fish and no plants you will also need to do partial water changes to remove the nitrates and other organic compounds from the water. If you keep sufficient numbers of plants, large water changes are usually unnecessary although small water changes of approximately 10% can be beneficial.
At certain times of the year or if the balance of fish, plants and biological filter is off you may still experience green water due to the build up of algae. The best method of guaranteeing clear water from this problem is through the use of an ultraviolet sterilizer. This device uses a small germicidal UV bulb which is placed in a pipe to allow water to pass all around and will give a near 99% reduction in algae when properly sized to the pond. However an ultraviolet sterilizer must not be used without adequate biological filtration, as the dead algae still needs to be broken down by the filter.
If you only occasionally have problems with algae or other suspended particles which interfere with water clarity then you might consider a flocculent which is made by several well known manufacturers of pond products. This type of product works by causing particles in suspension to clump together and then fall to the bottom where it must then be removed by siphoning or vacuuming from the bottom or a mechanical filter can be used to remove the debris.
Pond Balance
· Keep rain run-off out of the pond. It carries with it soil, fertilizers, and chemicals which will prevent the pond from balancing.
· If in full sun, shade 50 – 70% on the pond surface. Do this with the leaves of water lilies and floating plants. If your pond is in less than full sun, less surface coverage is acceptable.
· Use one bunch of anacharis for each two square feet of surface area. In small ponds (less than 25 sq. ft.) use one bunch for each sq. ft.
· Use no more than once inch of fish per sq. ft. of surface area initially. After the pond has fully established or with well filtered water, more fish may be added. Feed only what the fish can eat in 5 minutes. Uneaten food feeds algae.
· Add biological filtration and an ultraviolet sterilizer.
· Remove any dead organic matter from the pond
Seasonal Care
Spring
With spring approaching, we offer the following list of pond care suggestions to help get your pond off to a healthy start for the spring and summer growing season.
· Increase water circulation.
· Start feeding your fish again when the water temperature reaches a constant 50 degrees.
· Cleaning; it is a good idea to clean your pond once a year in either late spring or early fall. Remove all fish from your pond and place in a large tub of your original pond water (cover tub with netting so the fish cannot jump out). Try to keep the fish and plants in the shade while working. Remove all plants (keep wet!). Pump out all water and sweep up remaining debris with a broom and soft-edged dustpan. Rinse liner and repeat as necessary. Do not use any type of cleaning agents! Fill pond and de-chlorinate. Acclimate fish.
· Fertilize each plant and place at appropriate depth. Lilies and Lotus should be fertilized every 2-3 weeks, marginals every 5-7 weeks.
· Add Anacharis to prevent algae growth. (one bunch for each 2-sq. ft. of pond surface).
· Turn on Ultraviolet sterilizer after the biological filter is working properly and the water starts to turn slightly green.
· Add Microbe Lift (a bacteria to help jump-start biological filters and break down sludge).
· Divide and repot plants as needed.
· Add floaters such as water hyacinth and water lettuce (late spring after danger of frost has passed).
· A few things you may need: Fish net, Dechlorinator, Microbe Lift, anacharis, no-hole aquatic plant containers, aquatic plant soil (not potting soil), gravel, fish food, thermometer and Accu-Clear.
· Remember to continue fertilizing your plants.
· Remove dead foliage from the pond.
· Feed you fish well, (use fresh food)
· Maximize your aeration.
· Before the leaves begin to fall, cover your pond with one of several sizes of leaf netting. (It is much easier to keep the leaves out than to remove them after they fall into the pond)
· This is a good time to divide some types of aquatic plants (waterlilies and iris)
· Remove annuals from the pond as they will decay and pollute the water.
· After your hardy plants have stopped growing, cut back the foliage and lower the pot to the bottom of the pond.
· Stop feeding your fish after the water temperature has dropped to the mid to upper forties.
· Also when the water temperature has dropped into the forties, reduce the circulation of the pond water by either turning off the pump for the winter and draining all of the plumbing or preferably by placing the pump or the intake to the pump closer to the water outlet (waterfall etc) and pick up water from mid-level of the pond. Also turn down the water flow. Keeping the water flowing through your biological filter allows the bacteria to live therefore giving good water quality early in the spring.
· If you keep your filter running through the winter, you must take precautions against the freezing of water in your plumbing should there be a power outage.
· You can add a floating de-icer to keep an area free of ice. This opening is necessary during periods of ice cover to allow an exchange of gases.
· Water Hawthorns are a nice addition to the pond and sometimes bloom through the ice. They grow and bloom fall through spring and go dormant in the summer.
We recommend planting aquatic plants in no-hole plastic containers to minimize maintenance. Use a heavy clay loam (not potting soil). A soil that you would use to grow vegetables in will work well. Most aquatics require at least 5 hours of direct sunlight for optimum growth. Do not cover the growing point of water lilies with soil or gravel.
Tropical Water Lilies should be planted in a 3 – 5 gallon container. Fill the pot half full of soil and add 3 – 5 aquatic fertilizer tablets then pack the soil around the tuber, (which should be in the center of the pot) to within 2″ of the top. Add 1 ½ ″ of gravel and lower into the pond with 6″ - 12″ of water over the top of the pot. The water temperature should be at least 70 degrees. Fertilize every 3 – 4 weeks during the growing season.
Hardy Water Lilies should be planted in 3 – 5 gallon or larger containers. They are planted much the same way as tropical water lilies except that the rhizome should be placed at forty five-degree angle in the container. Hardies can have up to 18″ of water over the top of the pot. Fertilize every 4 – 5 weeks.
Marginal Plants should be planted similarly to water lilies in 1 – 5 gallon containers. Less fertilizer is required, 1 – 2 tablets per pot for most marginal plants. Fertilize every 5 – 6 weeks.
Oxygenating Plants should be planted in a one gallon container of pea gravel only. No fertilizer.