For Fountains (Indoor or Outdoor)
- When choosing a pump for your fountain there are two terms that you will see
when looking for your pump. GPH (gallons per hour) and "lift" or "head". For a
fountain the GPH is not an issue, that is a guide used for ponds. The lift or head
is what you will need to know. How far does the water in your fountain have to
travel from where the pump will sit in your fountain to the top of the fountain
where the water comes out. You will need a pump that lifts
higher than that measurement. If that distance is 24", than you
will need a pump that lifts at least 36" high. The "maximum
lift" means that is the maximum height that the pump will lift
the water. So you will get "0" flow at the maximum lift.
For a Waterfall or Pond Pump -
For a waterfall, the decision to be made is how wide you want your flow of water.
For every inch of stream width or waterfall "sheet you will need to pump 100
gallons per hour at the height you are pumping. For example, if the pump has
to lift the water up 3 feet to the top of the waterfall, you need a pump that will
move 100 gallons per hour at 3 feet.
For Ponds - It is best to
circulate the water at least once an hour. If you have a 500
gallon pond you would need a pump that moves 500 gallons per
hour at the height of the discharge.
For a Pond
Rule of Thumb - The
Length of tubing is also an important factor when choosing a
pump. Every 10’ of tubing equals the same restrictions as 1’ of
lift.
What size pump
does a pond need?
Recommended size of a pond pump is determined by:
1) Turn
Of Pond Water
For a
pond with a pressurized filter, turn the water approximately
once every two hours (example 1800 Gallon pond –
minimum 900 GPH Pump)
For ponds
with skimmers and falls and most other types of ponds, water
should be turned approximately once every
hour (example 1800 Gallon Pond – minimum 1800 GPH Pump)
2)
Height Water Must Be Pumped Above Pond Surface
The chart
to the right shows how GPH decreases
Head height
is the term for the vertical height the pump raises water
above the surface of the pond
All pumps
have a maximum head height (see head height demonstration
below)
3)
Selecting Correct Tubing Is Critical To Pump Performance
Correct Size Tubing Is Very Important:
Too small
tubing restricts water flow. The example below demonstrates
the importance of tubing size. The image above shows three
separate containers. Each collected the discharge from 700
GPH Pump for 10 seconds. The only difference is the tubing
size. Too small tubing will restrict the flow of water
dramatically.
Use the
chart below as a guide to assist in selecting the suggested
tubing for each pump size. It shows the maximum flow rate
for each size of tubing.
Why Knowing a
Pond’s Volume is Important
1) Gallons
in a pond will tell you the following
a. Size of
pump for you pond
b. Size of
filter for you pond
c.
Approximate Number of fish for your pond
2) How to
calculate approximate number of gallons in an existing pond
a. Volume
for rectangle ponds:
avg. WIDTH
x avg. LENGTH x avg. DEPTH = Pond volume (cubic ft.)
EXAMPLE:
10ft x 12ft x 2ft = 240 (cubic ft.)
240 (cubic ft.) x 7.5 gal = 1800
Gallons
b. Volume
for circular ponds:
RADIUS X
RADIUS X 3.14 X DEPTH = POND VOLUME (cubic ft.)
c. Volume
of a pond can be most accurately calculated by using a water
meter that can be connected to a garden hose while initially
filling pond.
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