So you want a fish pond or water
garden.
Useful Formulas
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When you decide on a spot for your
pond dig the hole before you buy
anything!
Then use the guides on the next few
pages to be sure you have the right
setup.
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Pond liner sizing: Measure the hole that you
have excavated. Add twice the depth plus 2 feet
for coping to get the magic number, then add
that number to the length or width of the hole
to get the liner size needed.
Do not exceed 10” of fish per 100 gallons of
filtration.
• Calculate your “effective” pond volume:
Average depth less than 2’ 6” add 25%.
Pond located in full sun add 25%.
• Size your pump to circulate your entire pond
in 2 hours (filtration pump)
• Know your pond’s volume in gallons.
Length X width X depth X 7.5. then add for
“effective pond volume” above when sizing your
filtration but not when adding chemicals.
• Size your waterfall pump: a minimum of 100
gallons per hour per 1” of weir width.
Pond Water Balance
The closer you get to nature the less
problems you will have.
People often come into the store in a
panic after spending an entire day
cleaning their pond spotless. The next
day the thing turns pea green. Its all
about the pond balance. They killed
all the beneficial bacteria and ended
up with an algae bloom.
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1. Balance of plants to fish.
More plants and less fish mean less green water problems
and cleaner water.
2. Balance of sun to shade.
More shade means less algae problems. However, less sum
means less blooms on your water plants.
3. Balance of Nitrogen Cycle. (Simplified version)
Fish food + Fish waste + Decomposition by fungi and bacteria
+ Oxidation by more bacteria = nitrates and nitrogen (plant and
algae food). Add some sunlight and algae and plants will
thrive. Floating plants do double duty to help combat algae as they
shade the water and use the nitrogen from the water.
4. Balance of plants to sunshine.
Plant coverage should be 60 to 80% of pond surface
area. Water Lilly’s, hyacinths, water lettuce and parrot’s feather are
excellent at shading the water surface.
5. With the exception of Lilly’s I recommend potting all water plants
in soilless media as they will pull all their nutrients from the
water. Lilly’s require soil and fertilizer in order to have good blooms
they benefit from fertilizer tablets shoved just near the roots (to
keep the fertilizer from the water use a heavy clay soil when
planting them.)
With proper filtration all the above rules can be broken!
1. The ultraviolet clarifier can correct all the green water problems
when properly sized to the pond and pump.
2. The biological and mechanical filter can remove suspended
particles and transform fish waste to usable food for your plants.
How to size your pond
pump
Pond pumps come in several
configurations.
The best is a high efficiency Magnetic
drive pump. Less power use but does
not pump water up hill very well. (a
sprinter.) Pond filter use.
The low efficiency pumps cost more to
run but can push water up hill better.
(a weight lifter.) pond filter or water
fall use.
Typical sump pumps are often oil filled
and not intended for continuous duty
operation. Do not use at all!
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Pump size (gallons per hour)
What the pump will do
76-90
1. Small spitter w/ less than 2’ hose
2. Table top fountain
3. Small fountain heads
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145-200
1. Medium and large spitter w/less than 6’ of hose
2. Medium statuary fountain w/less than 4’ of lift.
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250-650
1. Large fountain heads only.
2. Small biofilter
3. Small waterfall less than 5” wide and less than 1’ high.
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750-1000
1. Waterfall less than 8” wide and less than 2’ high
Medium Biofilter.
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1200-1800
1. Medium waterfall less than 12” wide and 3’ high
2. Large Biofilter.
Pump placement.
The pump should not be on the bottom of the pond and
not right near the water return. Pump placement is important
should your plumbing or waterfall leak so as not to drain the entire
pond and kill your fish. Spawning fish like a protected area with
very little water movement. Keep the plants away from the splash
they don’t like water on the wrong side of their leaves.
Water Plants
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Marginal or Bog plants - These are essentially the plants that
stick up above the surface of the water and provide height to
the pond. They can be planted into waterlogged ground or
more commonly into plastic planting baskets, which are then
placed into the water. Planting Depth: 6 - 8 inches
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Floating Plants - These floating plants have extensive root
systems that dangle into the water from the surface, these root
systems provide ideal spawning areas for fish like goldfish. They
often reproduce by budding and as such can be very invasive.
In some areas especially the USA they are prohibited by law
because of the fact that they can grow so quickly. Planting
Depth: Allow to float unplanted on the surface
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Oxygenators - These are plants that are not very visible, as they
are present under the water. But they can fulfill a useful role in
the pond. They absorb nutrients, and can help to reduce the
growth of algae in the pond. Calling them oxygenators can be a
misnomer as although they produce oxygen during the day,
they absorb it again at night. Oxygenation is best achieved
using a pond pump. Planting Depth: up to 18"
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Deep Water Plants - These plants have leaves that float on the
surface and roots that are firmly placed in containers on the
bottom of the pond. Water lilies are generally the best known
aquatic plant. They are available in an enormous assortment of
varieties and colors. Other plants like lilies are available.
Planting Depth: Variable up to 3'
Please Note: Big Koi 6” or larger can damage many pond plants.
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Filtration
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Gravity out filter.
The good-- never restricts the flow of water,
clean it when you want to, great biological
action, easy to clean.
The Bad– hard to hide, must be positioned above
the water level of the pond.
• Pressure out filter
Pressure filter
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The good– Can be mounted anywhere, water
leaves the filter under pressure so it can run a
waterfall or spitter.
The bad– Most restrict the flow of water as they
become dirty forcing you to clean them.
Water fall and skimmer
filters
• Water fall and
skimmer
combinations
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The good- easy to clean helps
reduce leaves and other trash from
falling to the bottom of the pond
The bad- bigger pump more electric
use, professional installation
recommended.
Pump can burn out when starved
for water.
Waterfall must run non stop.
Water fall can leak when debris gets
in the stream or waterfall.
Submersible Filter
• The submersible filter
• Submersible filters are simple in design and
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ease of use. Toss them in and plug them in and
you are done.
They can run a spitter or very small waterfall
Designed for small ponds less than 700 gallons.
The down side is that you have to remove them
from the water to clean them.
• The ultraviolet clarifier.
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Ultraviolet Clarifier
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The good--an ultraviolet clarifier kills the green water
algae.
The bad—pricy, requires constant electric and water
flow.
Sized to the total adjusted pond volume.
Size the pump to turn over the entire pond once every
two hours.
If the pump is too small reduced effectiveness .
If the pump is too large (pumps water too fast) the
algae will not have enough contact with the light and
reduced effectiveness if any.
In a perfect world the pump, filter, and UV lamp will be
sized correctly for your pond and very little
maintenance will be required.
Stream from filter to pond.
To hide the filter we put it
behind the fence
The stream idea was good
but the plants were not. They
grew and blocked the stream.
Stream runs to old pond
from filter.
The return pipe is buried
in the stream
The filter is hidden behind
the fence and water
returns down the stream
The lilly would be happier
if the turtle was not
shooting water on the
leaves. The grasses are
great for filtration but will
soon overtake the pond
Note focal point. Tall stuff
as a backdrop.
Nice use of hardscaping,
focal point, caution about
inside of pond design and
kids / animals
Looks great now but
waterfall will soon be a
problem when algae and
leaves divert the water
flow. This is the most
common pond loosing
water complaint
Notice how large the field
stone is at the edge of the
pond. No worry of freeze
and thaw shifting the
edge.
Smaller fieldstone along
the edge will be a problem
over the years and is
dangerous. The marginal
plants will soon hide the
waterfall.
Great example of focal
point and easy to
maintain. Easy to clean
skimmer. gravel no mulch,
good view from the deck,
taller plants garden in the
back.
To avoid box filter a
stream runs around the
back of the pond. Always
running at a slow rate of
speed. Fieldstone
placement very poor and
will be problematic.
Notice waterfall in the
back, good view and
sound form the deck and
house.
Field stone arranged
poorly looks sloppy and
dangerous. Use very large
pieces along the edge to
avoid shifting
River rock instead of field
stone. Easy to install and
maintain, deer resistant,
more natural look. Mulch
could be a problem.
Notice how the liner is
lined with large river rock.
Safer for kids, pets and
deer resistant.
Poor design using mulch
up hill of the pond. The
mulch plus rain water
turns the pond like weak
tea.
Notice the bog plants in
the living filter in the back
of the pond. Slow water
always running through
the adjoining bog filters
the water.
• Summary
• Take your time and do it right the first
time.
• Plan your water garden as you would a
perennial garden.
• Oversize your filter and uv lamp but
not your waterfall pump.
• Read a book.