How to Select a Water Pond Pump

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How
to Select a Water Pond Pump.

By
the Pond
Lady

Pumps
come in a confusing array of models and sizes.You will
need a pump if you are planning on moving water in your
pond, whether by a waterfall, stream, fountain, or spouting
ornament. This article will help you determine what
size of pump you will need for your pond or water feature.It
will not matter whether the pond has a liner, or if
it is a preformed pond.

To
operate any electrical equipment near a water garden,
use an outdoor outlet. Set this outlet at least 6 feet
from the water and use only an outlet that is equipped
with a ground fault interrupter (GFIC) for safety. These
devices will cut off the power the moment water is detected
in contact with the wiring. Your cable should be protected
in a conduit, a plastic tube for electrical wires, so
you won’t dig into it accidentally. Extension cords
with an integrated GFIC can be used for shorter distances.
You can hide them under stones or mulch.

Pumps
are available in both submersible and external (out-of-pond
models). Reputable water garden suppliers have charts
and other information available that can help you select
the best model and connecting equipment for your purposes.
For the smaller pond, a submersible pump is the most
economical.

Pumps
are sized by gallons per hour (GPH) output at one foot
of lift or height. Larger capacity pumps are rated by
horsepower (hp). Manufacturers offer charts that break
down the power of each size pump according to incremental
heights of one foot. Some companies label pumps by GPH
while others assign letter or number designations that
require cross-referencing to charts.

It
is recommended that the water in a basic pond be turned
between ½ to 1 times per hour. A 500-galon pond
should have at least a 500 Gallon Per Hour pump. When
sizing a pump for a pond there are a few other considerations.
How high will the pump have to lift water? Will there
be a waterfall, fountain or statuary? Will there be
filters? All of these variables reduce the amount of
flow, which could affect water quality and clarity.

To
determine the pump required for your pond, estimate
the vertical height from the top of your pump to the
top of your waterfall or stream. Add another foot of
height or lift for every 10 feet of hosing you will
be using. This will allow for loss of volume from resistance
within the hose. A general rule of thumb is to figure
your stream/waterfall requirement as 150 gallons per
hour per inch width of the spillway or channel. For
example, if your stream or waterfall spillway will be
10 inches wide, you will need a pump that produces a
flow of 1500 gallons per hour (at whatever combined
height of the feature and another foot of height for
every ten feet of hosing to get there). You can use
a valve to adjust the pumps flow to what you want. You
cannot increase the pumps capacity. ALWAYS PURCHASE
A PUMP THAT WILL MORE THAN HANDLE YOUR NEEDS.

Submersible
pumps are placed directly in the pond.They are free
of distracting noise and can be used to drain your pond
when necessary. These pumps do have a disadvantage.
The pump seal can rupture, sending oil coolant into
the water. This can prevent surface gas exchanges, thereby
endangering your fish. This happened to my pond only
weeks after the pump was turned on. I would recommend
the new magnetic-drive pump, which avoids the use of
coolants. They are more expensive to buy but are far
less expensive to operate.

I
have been asked many times if you can use a swimming
pool unit. This is very impractical for most people
because they are very difficult to maintain. A pond
has far more organic particulate matter (small separate
particles) than a chemically maintained swimming pool.
Sand is a fine medium that quickly clogs with debris.
“Channeling,” in which water runs in limited
paths, avoiding most of the filtration media, often
occurs so that daily or frequent backwashing is required.
Some pond keepers have adapted these units by using
larder media, such as a proportion of gravel. Gravel
is heavy and difficult to clean.

To
select a pump, you will need to know how many gallons
of water there are in your pond and what type of filtration,
if any, you will be using. If you have a preformed pond,
refer to the specification that comes with the pond.
To calculate the water volume in a flexible-liner pond,
see the chart below.


Calculating Water Volume

Rectangle
Ponds. Length in feet x width in feet x depth in feet
=cubic feet Circular pond. 3.14 (1/2 diameter in feet
x 1/2 diameter in feet) x depth in feet = cubic feet.
Free form shapes. Break the pond down into a series
of rectangles and circles and figure the volume of each
area separately, then add the volumes together. Each
cubic foot contains 7.5 gallons of water, so multiply
the total number of cubic feet times 7.5 to determine
the total number of gallons.

Recommended
Tubing Diameter For Pumps To Waterfalls.


1/2-inch diameter for flows up to 120gph
3/4-inch diameter for flows up to 350gph
1-inch diameter for flows up to 1000gph
1 1/4 inch for flows up to 1500 gph
1 1/2 inch for flows up to 3000 gph

Note:
Thanks and credit goes to two wonderful friends, Helen
Nash and Marilyn M. Cook, and their book ” Water
Gardening Basics” Published by “Sterling Publishing
Co.”

Safety
Tip:
To avoid accidentally pulling a pump cord out
of its safety seal, secure the cord to the lifting handle
on your pump with a plastic tie wrap. This will put
the strain onto the pumps handle and not the cord.

Darlene
Jennings (pond Lady) President,
Mid-Michigan Pond & Water Garden Club
Advanced MSU Master Gardener

 

 

How to Choose a Pond Site
Designing a Pond
Edging for a Pond
Pumps
Spring Cleanup
Plants
Summer Cleanup
Waterfalls
Water Gardens
Winter

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Lady
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