Page 304 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

302 INTRODUCTION TO POND FISH

Construction choices life span; if choosing PVC, select a thicker grade, typically
The availability of modern pond construction materials 1 mm, with a reinforcing nylon weave providing extra
provides a wide choice for the hobbyist. Creating a pond using strength and durability. Preformed pond units are also
flexible pond liner or installing a preformed pond unit (see box, available in a range of materials, of which rubberized versions
below) does not require advanced construction skills and can are generally the most durable.
be relatively inexpensive. Large concrete ponds, by contrast, Flexible pond liner is sold by the square foot, in rolls
are considerably more expensive and may even require the of various widths, so careful planning is required to be sure
services of a professional installer. you purchase sheeting of the correct dimensions. The
A wide range of flexible liners and preformed pond units amount of liner required is easily determined for any shape
are available to suit most budgets, but it can be a false economy of pond using the following method. First, determine the
to purchase the cheapest option. Less expensive liners, such length of the pond at its longest point and the width at its
as polyethene, may not last as long as higher-quality flexible widest point. Next, adjust these dimensions to allow for
liners, such as PVC and butyl rubber, which are more sufficient liner to fit into the deepest part of the pond: to
resistant to attack by the ultraviolet component of sunlight. do this, multiply the maximum depth of the pond by two,
Butyl rubber is probably the best material to choose, partly and add this to both the length and width figures respectively.
because it is very elastic and so will not crease as much Finally, add a further 18 in (45 cm) to each dimension to
during installation as other materials. A PVC pond liner is provide extra liner to overlap the edge of the pond; the final
a somewhat cheaper option, with a correspondingly shorter figures give you the overall width and length of liner required.

FLEXIBLE LINER OR PREFORMED POND UNIT?

FLEXIBLE POND LINERS PREFORMED POND UNIT
Building a pond using flexible liner is Preformed units made from plastic,
relatively straightforward and allows you to fiberglass, or rubber are quick and easy
exactly tailor the design to your needs. All to install and are manufactured in a wide
types of liners must be used with a suitable range of shapes and sizes. Many designs
underlay material, which cushions it from include a shelf around the edge for
sharp objects; commercial products are cultivating marginal plants. Pale-colored
available, but large pieces of old carpet units should usually be avoided, because
or a layer of sand can work just as well. they can look artificial.

PROS CONS PROS CONS
• Can be used to create any • Can be punctured quite • Very easy to install, once • Units are molded to fixed
size or shape of pond and is easily by the roots of some the area has been prepared. shapes, which can constrain
ideal for a more natural look. plants, requiring repair. • A wide range of shapes and pond design.
• Durable; top-quality liners • Cheap liners can have a short sizes are available, including • Some styles may not be deep
can last for up to 50 years life span and are a poor choice. units that are large enough enough for safe overwintering
before needing to be replaced. • Requires underlay, which to accommodate koi. of fish.
• Suitable for use either in can add to the cost. • Can be used both in the • Fairly durable, but if split or
the ground or raised above • ground and for creating a otherwise damaged by invasive
it within a brick support. Silt can build up in folds raised or semi-raised pond. plant roots, they are not
or creases in the liner and can easily repaired.
be difficult to clean out.

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