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POND CONSTRUCTION
Your pond should be
built after you have seen a few others. There are different
philosophies and construction methods. You should know what kind of
pond you want Koi, Garden, Cichlid, or Goldfish. You should learn
what filter system you want and why. Learn from others. Read as many
books and magazines that you can. If you are going to hire a
contractor, know what you want completely. Here are a few ideas. If
you can not decide what kind of pond you want, do like I did.
Make one of each. From Charles Lewis
A Guide To Modern Pond
Construction
Most of us will have
started keeping cold water fish and then after seeing Koi at a Koi
dealer or at a garden center decided that this was the way to go
regarding our fish keeping. Many of us will have started with a
small, or not small, ornamental pond with very little depth and
usually many plants including water lilies. These are very
ornamental and look nice in the general setting of the garden, but
totally unsuitable for the successful keeping of
Koi.
Let us assume that you
are now intending to build a pond and these notes are now intended
to give some ideas and recommendations for your consideration
before you make a decision.
There is a big
advantage in belonging to a local Koi club because then you can
visit other members' pond , exchange idea, often a club has books
in the library which shows photographs of various ponds. There are
now quite a few photos of ponds appearing on homepages on the
Internet.
Let us now start
looking at some of the things to consider before designing your
pond. The position of the pond, the size and the shape will
inevitably depend on one another so you cannot really decide on
one without the other.
The first idea is to
place the pond near to the house so that you can admire your fish
even when it is cold and windy day.
You should keep the
away from large trees as the roots especially in the case of
species such as Weeping Willows will seek out of water and can
damage the ponds especially in the case of pond liners. Bamboo has
the same effect and will soon put down long roots and will easily
penetrate the pond liner.
Safety
Safety is another
consideration especially if you have young children. Your children
may be grown up, but you are going to have grandchildren too.
There is also the danger of children getting into the garden from
next door. Children are very persistent when there is water
around, and they cannot be watched all time. Another consideration
is how close to the house you should build it. It must be
remembered that with a six feet deep pond below ground then with
the foundation and base with the initial hole will be eight feet
deep and especially if there is heavy rain then there is a danger
of the sides collapsing and even undermining the foundations of
the house it self. If you are building the pond close to the house
then it is important to get professional advice or swimming pool
builders that would put up temporary retaining structure
when digging as deep as this. There is always a danger of a caving
in especially digging out trenches. When working in this area make
sure there is someone above ground, who can be at your assistance
in case of accident.
Type &
Shape
The first thing to
decide if you want a formal or informal pond above or in
ground.
Size of
Pond
Everybody likes to make
their pond as large as possible, but there are several things to
take into account. The larger the pond the more maintenance and
personal effortwill be required. To keep the pond in top condition
for your fish.
Cost
Contractor electrical
transport consultation aeration pump work landscaping
- after service feng shui design - filter media - waterfall
(artificial or river rocks)
Bridge pagoda
tables and chairs pvc pipe and
fitting.
Depth of
pond
It is generally agreed
by all books and experts on the subject that the pond should be
six feet deep, and if you are building a large pond say 18ft x
12ft this is probably correct and looks right when completed. If ,
however you are building a much smaller pond then this depth does
look completely out of proportion. In these case as it much better
to have the pond say if the minimum depth 4 foot 6 inch with the
depth of 5ft in way of a bottom
drains.
Bottom
drains
It is generally
accepted that bottom drains are a must and should be fitted to all
ponds under construction. These are a few cases where it is not
possible to connect into the main drains but even in those cases
the problem can probably by overcome by use of a soak away. If the
main drain is above height of the pond then it is possible to have
a discharge chamber, and then you can pump it to the drain, using
a pump with a float level fitted.
The number of bottom
drains required will depend on the size and shape of the pond and
also the preference of the owner. With a rectangular pond say 12ft
x 10ft then two bottom drains would be normally used, and with a
pond by 18ft x 12ft then three bottom drains are usually
used.
Filter
System
We will now look at the
filter system for the pond. This must be considered when you are
designing your pond system, and you must decide on this important
item before acommencing to construct the
pond.
Many Koi keeper can
quickly decide on what size of pond they want, but in many cases
they do not have enough space to have a filter system big enough
to support their designed pond.
When you have decided which type of
pipe you are going to use then you need to decide if you are going
the bottom drains directly to the main drainage or to the
settlement chamber of the filter system. The sketch below show the
different ways of doing this.
The diagram above shows a typical
pond layout where the bottom drains go direct to waste, and the
feed filters are taken from mid
water.
The stand pipes in the discharge
chamber can be lifted to release the water to the main drain.
Slide valves used instead of the stand
pipes.
The diagram above shows another pond
layout where the bottom drains constantly feed the first bay of
the system, which in fact is the settling chamber. The drain from
the settling chamber is connected to a slide stand pipe, in the
discharge chamber.
This method continuously removes
waste from the pond, but it is necessary to have a very efficient
settlement which is cleared
regularly.
The surface area of the filter system
should be one third to one half of the surface area of your pond.
This will important as when your fish grow, and the pond is
heavily stocked with fish then the filter will still be able to
provide good water quality and so ensure your fish can be
maintained in good condition. It is important to know the exact
gallonage of your system. The exact volume is important to
ensure that dosage of medication can be applied accurately at a
later stage. It is also a good idea to know the capacity of your
pond and your filter system
separately.
Filtration
method
Mechanical biological chemical
vegetable sand pressure filter trickle
tower
Settlement chamber feed by bottom
drain or forced removal dirt with air pump and uniring timer (to
remove the waste at regular intervals timer operates at one minute
at preset intervals) or using vortex chamber for removing
dirt.
Mechanical filtration is the only
really filtration. All the others change the nature of chemicals
they come into contact with.
Biological processes to purify the
water bio filter supports a colony of aerobic bacteria that
convert toxic ammonia to nitrites then to nitrates which is
absorbed by growing plant as fertilizer and plant protein becomes
food for the fish thus complete the cycle.
Chemicals which extract organic
wastes, inorganic chemicals & carbon dioxide from the water
zeolite activated
carbon
zeolite 1kg + 50 gal
water
carbon 1kg + 50 gal
water
Flow
rate
Must be in tune with filtration
processes at work. Too powerful circulation will prevent the build
up of beneficial colony of bacteria by tending to dislodge
them.
Mechanical removals of solids
detritus as the water passes through a suitable medium such as
"Clarenet" "Bristle Brushes" "Synthetic Fiber" or
Vortex
The second purpose of a "Proper" Koi
pond filtration system is that of a biological filtration Koi
produce toxic substances that become totally dissolved in the pond
water and cannot be strained out by mechanical
means.
It is important here to understand
that a good biological stage is not intended to be a "strainer as
in mechanical stage".
Filter
Media
Baked clay granules ammo rocks
gravel coral sand foam brushes flocor bio home
plastic moulding synthetic fibers cartridges brushes
springflo siporax etc.
The next stage is a chemical or
vegetable filtration
Final to polish the water use of sand
filter and trickle tower.
An overflow is usually incorporated
in one of the bays so that the pond water cannot go above a
designed level.
Figure shows the general layout of a
simple 3 bay filter system, and this is what you should aim for.
On the right hand side water enters the filter system from either
the vortex chamber, mid water suction, or
drains.
The water then goes to the bottom of
the first chamber and then raises up through the media grids and
the top of the chamber. This water will then overflow over the
weir, and so to the bottom of the second chamber process continues
as it did in the first bay. When it reaches the last bay it is
pumped back to the pond
There has been quite a
lot written about these chambers, and I have seen several comments
which said they cannot work because centrifugal force requires
very high revolutions. This is true if you are comparing it with a
real centrifuge, but even at the speed at which the water goes
around the chamber it is sufficient for the heavier solids to drop
to the bottom and remain there until they are drained away. The
amount removed in this way proves that it is working Smaller
floating debris like algae will not be removed, and will still be
carried over into the first filter chamber.
The efficiency of the
unit does depend a lot on its design especially the diameter,
height, and especially the positioning of the inlet and outlet
pipes. The pumping rate can also be very
important.
If you have any doubts
about the efficiency of a vortex chamber then do try to visit a
pond keeper that has one in use as I am sure you will be quite
impressed with it.
This rough sketch shows
the basic idea for the Vortex chamber. The inlet from the bottom
drain passes through the inlet just above the cone section of the
chamber. The inlet is positioned so that the water flows around
the side of the vortex, and then rises up and out through the
outlet at the top, and then passes into the first chamber of the
filter.
The solids will then
fall to the bottom of the cone, and can then be flushed out to the
main drain several times a day with the minimum loss of pond
water.
When someone is
starting to dig out their pond they often ask what size to allow
for the vortex chamber considerably in size. Even when you have
decided to have a 36 ins or 48 ins diameter unit the heights do
manufacturer to the other. They can be from 36 ins high up to 84
ins. For this reason it is essential to pump before you start
digging so that then you can dig out the area where the chamber is
to be fitted to the cone.
Quite a few of these
vortex chambers are free standing, but some of them have to be
buried in the soil. They should be stood on a six inch thick
concrete base.
In the case of
connection to a Vortex then it will be necessary to use more than
one elbow to connect up is still necessary to make the flow as
smooth as possible.
Circulation
Example
System up to 5.5 tons
(1,200 gallons), Flow rate approx 550gph
System up to 12
tons (2,600 gallons), Flow rate approx 950 -
1,150
System up to 30
tons (6,600 gallons), Flow rate approx 1,800 -
2,000gph
Pump
Output - watts -
cost
Air pump - 60lph - 80lph - 100&
120lph
What to
include in the walls
Whilst we are building
the walls we must remember that there are some pipes and items
which must be included in this stage. Consideration of the
following should not be neglected :-
a) Power skimmer
b)
Return from power skimmer
c) Return from main pump
d) Deep
water return
e) Mid water section
f) Water fall
g)
Venture
h) Spray bar
Power skimmer is an
important item for removal of any leaves and surface debris, and
they make a remarkable difference to the clarity of the surface
water. They are fitted with a basket, which can be removed for
removing the leaves, etc. when the pump is shut
off.
Applying
proper system maintenance
Pull bottom drain
regularly (if no uniring)
Partial water change (10% daily
change)
Keep pond & filter as clean as possible
No
overstocking
No over feeding
Quarantining new
fishes
Observing pond & Koi closely
Regular water test
(Ammonia, Nitrite, Nitrate, pH, do and
Hardness)
Don't
try to keep Koi, learn how to keep water, then the Koi will "keep
themselves"
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