Key Points:
·
Before construction, determine the size and location of the water
feature.
·
The two most popular pond materials used today are the EPDM flexible
liners or the plastic preformed pools.
·
For larger water features, pool hardware (pumps and filtration systems)
is a necessity.
·
Aquatic plants help keep pond water clear and provide shade and
protection for fish.
Before you start any water
feature you must determine its size and location. There will be both budgetary and physical
limitations on the size of pond you have in mind. If you want fish, a larger pond is best
because there’s greater temperature stability. A larger pond gives you the
option to add more fish or aquatic plants.
If you have a small yard or a limited budget, a smaller pond will be
best.
Prime consideration in selecting a pond site should be given to the viewing area. A well-located pond can be enjoyed from your patio or deck without the need to establish a new viewing area. The pond should be located where it gets sun for part of the day. Five to seven hours per day is ideal for allowing aquatic plants to thrive and flower. If possible, avoid areas directly under trees because they can be the source of leaves and other debris (seeds and flower parts) that can foul the water. Tree roots can also damage pond liners.
Homeowners have the choice of flexible liners or
preformed ponds (shells) to hold the water in place for their water feature.
When it comes to flexible liners, EPDM (ethylene propylene diene rubber
membrane) is considered the best. The
thicker grade (45mil) has a 20-year warranty, does not deteriorate with
exposure to sunlight, and is safe for fish and aquatic plants. To determine the size of liner needed for a
naturally shaped pond, draw an imaginary rectangle around it and measure length
and width. To each of these measurements
add twice the pond’s maximum depth plus 2 feet to give the necessary surplus of
material to extend beyond the edge of the excavated area.
Preformed ponds are available in a range of sizes
and shapes with pre-molded shelves for plants. They can be made of plastic or
fiberglass and are easier to install than liners. The plastic preforms are less costly than the
fiberglass ponds and flexible liners.
Any style of pool - formal, informal or something in
between - can be built with any of these materials. However, some combinations make good sense:
flexible liners are a good choice for informal pools because they can take any
shape at all, while a perfectly round formal pool would be easier to create
with a preformed shell.
As you design your pond, especially larger ponds,
keep in mind the need for pumps and filters to maintain water clarity and
aeration. Of prime importance is the
pump which circulates water and powers
filters, aerators and other water features (fountains, spitters, etc.). Pumps range from 75 gallons per hour (GPH) to several thousand GPH. The pump should be powerful enough to
circulate the water of the entire pond at least once every two hours.
A filtration system is typically needed to maintain pond clarity. There are two types of filters: mechanical and biological. Mechanical filters rely on foam pads or brushes to capture debris and small particles suspended in the water; they must be cleaned periodically. Biological filters are the most important for the pond; they are used to keep the water quality in check by providing a habitat for beneficial bacteria which remove harmful ammonia and nitrites. These filters allow water to flow through various types of media including pads, brushes, and specially designed plastic forms; they have extensive surface area that allows beneficial bacteria to colonize. As the water passes through the bacteria, ammonia is transformed into nitrites and nitrites into nitrates, providing healthy water for both plants and fish.
Choose visually intriguing and functional plants by considering both the ornamental and practical value of each plant. A good combination will oxygenate the water, compete with algae to keep the water clear, and take up nitrogen to balance the pond's ecosystem. Before buying pond plants, develop a plan. The number of plants needed will be limited by the size of your pond or container. The general rule is that plants should cover no more than 2/3 of the water's surface. Good air circulation is needed to allow plants to flourish free of disease. Plan on rapid growth of the small plants you start out with; they will quickly require more space. Be sure to include plants from each of the four categories of pond plants listed below:
Floating Plants -- float freely on the surface and their roots dangle
in the water. They can be placed in all
areas of the pond. They grow quickly and require periodic thinning. By shading
the water with their leaves, they reduce the amount of light needed for algae
to grow. Examples include Water Hyacinth,
Water Lettuce and Azola.
Surface Plants -- have their roots in soil and leaves on long stems
that float on the water's surface. By blocking sunlight, they also inhibit the
growth of algae. Water Lilies are surface plants. Tropical or hardy, they are
easily grown and make great plants for the average pond or container water
garden. One thing to remember with Water
Lilies is that they like calm water.
Never place them near splashing or moving water. Other surface plants include Lotus, Water Hawthorne, Variegated Four-leaf
Water Clove, Floating Heart, Water Poppy, Moneywort, and Parrots Feather.
Marginal or Bog Plants -- prefer their roots and
lower parts submerged. They may be planted in the shallow areas of a pond or in
very moist soil at the edge. In the pond, they compete with algae for available
nitrogen. Black Taro, with its large burgundy to black heart shaped leaves,
contrasts well with the tall sword-like foliage of Sweet Flag or variegated
Sweet Flag. Other interesting marginal plants include Zebra, Corkscrew and Horsetail
Rush, Aquatic Canna, Purple or Pink Pickerel Rush, variegated Water Celery,
Water Calla, Cardinal Flower, Dwarf Cattail, Horsetail, Blue Moneywort, and Houttuynia.