Pottery or concrete
bowls and containers offer an array of style and color. You can
easily incorporate them into existing landscape settings. Usually,
the only modification required for pottery is to plug the drainage
holes. Some concrete pots absorb water over time; this can stopped
by painting the interior with fish-safe waterproofing paint.
Depending on your climatic conditions, you may have to drain
and store pottery or concrete in winter to protect it from cracking.
Metal containers such as watering cans and washtubs make great
water features. Take extra care when running electrical cords
over rough metal edges. The biggest concern with metal containers
is rust. Most useable metal containers are tin or galvanized
steel treated to make them rustproof. As with concrete containers,
it may be beneficial to coat the interior of metal containers
with fish-safe waterproofing paint since seams sometimes leak.
Copper makes a fabulous medium to work with, due to its rust
resistance and the patina it develops. Avoid copper if you want
to raise fish. Copper containers and copper fountain units leach
copper into the water, which can reach levels toxic to fish.
Lumber and concrete blocks give structural support for container
gardens and water features using flexible liners. Select pressure-treated
lumber, composites, cedar or redwood because they withstand the
weather. Concrete blocks, either the grey building variety or
segmented retaining wall blocks, are sturdy and weatherproof.
Talk with a construction expert before choosing either wood or
The advantage of using wood or block combined with a flexible
liner is that you can produce almost any shape and size of enclosure.
Make custom-built containers part of a deck; incorporate them
into an existing wall or other architectural feature. Wood usually
costs more than block per unit of pond surface area. However,
it does facilitate designs that are more intricate. When picking
a material, consider your experience working with that material
and your available tools.
Many water garden centers employ concrete blocks or wood timbers
for display ponds because of their quick construction and durability.
Even on larger projects, wood and blocks offer great potential.
Factors such as humidity, termites and freeze/thaw cycles influence
your choice; either material can perform successfully in most
If your project involves a water garden or a koi pond, then
choose between rigid and flexible liners. Your liner material
choice affects other areas of construction. Rigid liners allow
little or no flexion from water or ground pressure. At the other
end of the spectrum, flexible liners move with the substrate
they line. Rigid liners include plastic, fiberglass and concrete
formulations while flexible liners encompass PVC (polyvinyl chloride),
vinyl, EPDM (ethylene propylene diene monomer) and butyl products.
A composite liner, spray-on urea liner, blends the best features
Nearly everyone has seen the ubiquitous preformed pond unit.
Once the mainstay of the hobby, preformed fiberglass and plastic
shells come in many shapes and sizes for the homeowner to create
a little oasis quickly. Marketed as easy-to-install without the
hassles associated with liners (tears, punctures, roots, etc.
. .), preformed units enable anyone to create a water garden
in an afternoon.
When choosing a preformed unit, the tradeoff is ease of installation
versus design constraints. Preformed units can be hard to disguise
and naturalize, but for those not interested in an advanced setup,
they are just the thing.
The biggest concern for fiberglass and plastic is temperature
and frost depth. Plastic preformed units flex and deform more
than fiberglass units do during freezing weather, especially
where ground heave occurs. Flexing sometimes prevents damage,
but in extreme conditions, cracks or creases may damage plastic
and fiberglass structures. Both materials weather well over time
and quite often outlast the pond itself.
Plastic and fiberglass units are fish safe. Complement them
with various preformed stream and waterfall units. They readily
accommodate filters, fountains and other accessories. The cost
of preformed units is significantly higher than using a similar
sized flexible liner, but many homeowners choose preformed ponds
because they find them easier to install. Less common rigid liner
structures include metal or plastic livestock tanks, childrens
swimming pools and concrete structures.
By far the most complex and expensive type of rigid liner
is concrete. Yet you can easily justify the expense when you
consider the value of show-quality koi that thrive in properly
built concrete koi ponds. Modern concrete koi ponds use fiberglass-reinforced
concrete to add flexibility and tensile strength. Flexibility
helps to prevent concrete from cracking.
While very similar to swimming pool construction, concrete
koi ponds have some unique characteristics of their own. The
plumbing and filtration systems dwarf that of a pool and water
flow rates are much greater. Without the benefit of chlorine
and other chemicals to combat algae, UV sterilizers and clarifiers
work in conjunction with the latest bio filtering technology
as opposed to sand or bead filters common in swimming pools.
Materials used for concrete construction typically entail
reinforcing grid or mesh, the concrete itself and various plumbing,
electrical and filtration components. Apply concrete with either
a wet gun technique (Shotcrete)
or a dry gun approach (Gunite). This oversimplifies the process;
for most homeowners I recommend leaving the installation of concrete
koi ponds to professionals.
Shotcrete and Gunite facilitate creative design opportunities.
Many better-quality contractors construct realistic looking rocks
and waterfalls with these systems. Natural stone is expensive;
a Shotcrete or Gunite waterfall makes a cost-effective alternative
to quarried stone. You can use concrete in unstable soil conditions
unsuitable for liner ponds.
Concrete ponds necessitate a significant outlay, especially
considering the filtration, heating and plumbing associated with
state-of-the-art koi ponds. Nevertheless, this cost pays off
taking into account their life span, no concerns over liner damage,
superior design capabilities and the fact that most concrete
pond owners also have a substantial investment in their prized
As with other material types, there are always concessions
to make. Besides the high initial investment, the other downside
of concrete is potential for cracks. The scale and scope of concrete
koi ponds also rule out most homeowners tackling the task themselves.
Perhaps the biggest negative for many with concrete is not the
cost, but its permanence. Typical pond owners modify their ponds
approximately every five years. With concrete, once you make
the pond, it is not cost effective to redo it on a regular basis.
In contrast to the permanence of concrete ponds, flexible
liners take into account the ever-changing nature of water gardens.
By far the most popular choice today, flexible liners give builders
the option to fashion almost any shape and size of koi pond or
water garden. The most significant advantage of flexible liners
is their versatility. Flexible liners cannot compensate for poor
planning or sloppy excavation work. However, they are excellent
materials for most applications. This category of liners includes
PVC, vinyl, EPDM and butyl.
All About Flexible
After deciding the basic structure or shell, the
next material to consider is tubing or pipe. Many factors influence
the plumbing that circulates water.
All About Pipe