When Replacing a Fountain Pump or Choosing a New One
"Head" : This is the maximum vertical
lift of the pump. For example, a 6' head means the pump is rated
to pump water up to 6 feet high. Note, however, that at 6 feet the
pump would be providing very little water, with gallons per hour
around zero. So if you need to pump, say, 200 gph at 72”,
you will probably need about a 300-600 gallon per hour pump to do
the job. See a "pump curve" for the amount of water pumped
to various heights. Major pump manufacturers like Cal Pump, Fountain
Tech pumps, and others, include pump curves on their boxes, brochures,
or other literature. You should take a good look.
"GPH" : Gallons per hour, usually rated
at different heights
"GPM" : Gallons per minute, usually rated
at different heights
"Pump Curve" : The amount of water volume
"curved" according to various heights. A 500 gallon per
hour pump, for instance, might pump 500 gallons per hour at 0”
lift, 350 gallons per hour at 24” of lift, and so forth. When
buying a pump for the first time or when seeking a replacement pump,
it is essential that you know how many gallons per hour you want
to pump and at what height (head).
"Water Volume" : The total volume that
you will be pumping is controlled by a few factors. One factor is
the size of the pump, as covered above. But you also must consider
how wide your tubing will be. Tubing is measured in two ways: inside
diameter (i.d.) and outside diameter (o. d.). Very skinny i.d. tubing
will greatly reduce water flow. Many customers are shocked when
they find that, after hooking up their 500 gallon per hour pump
to ½” inside diameter tubing, they are only getting
what they consider a trickle. Well, we had an engineer do some calculations
for us to illustrate the problem. Using a 300 gph pump with ½”
tubing is going to restrict your flow to 253 gallons per hour. By
increasing the pump to 450 gallons per hour, but still using ½”
tubing, you will increase volume only slightly, to 264 gallons per
hour! The lesson is this: When purchasing a pump, find out what
size of tubing is supposed to go with it. Another problem is running
the tubing too far. Long lengths of tubing create resistance. If
your pump calls for ½” i.d. tubing, for instance, but
you are running the tubing twenty feet from the pump, it is a good
idea to use ¾” tubing instead so as not to cut down
too much on flow.
How much water do I need? What size of pump?
This question is answered in part by whether you want a “trickle”
or a roar. When you buy a fountain, you will usually find a recommended
flow. For waterfalls, use this as a rule of thumb: for every inch
of stream width or waterfall "sheet," you will need to
deliver 100 gallons per hour at the height you're pumping. So if
you are building a 12” wide waterfall that is three feet tall,
you need to buy a pump that will be pumping 1200 gallons per hour
at three feet of height. For ponds, whenever possible, it is a good
idea to re circulate the water once an hour, more often if possible.
Thus, if your pond is 500 gallons, try to buy a pump that will re
circulate water at a rate of 500 gallons per hour. For really large
ponds, this is not necessary and is far too expensive. For a nice
waterfall effect, we usually advise about 4000 gallons per hour
or more at the top of the waterfall. This creates enough volume
for a wide, crashing spill. Adjust stones to soften the splash if
desired.
When Is an External Pump Appropriate?
“In-line” pumps provide the "most bang for the
buck" in two ways. For one, the purchase price is quite reasonable
for the high volume of water being pumped. But even more importantly,
these pumps dramatically outperform typical submersible pumps, cutting
electrical costs two to three times. Since electrical costs for
a large pond can easily run from thirty to one hundred dollars a
month, choosing the most energy-efficient pump is tremendously important.
However, if you need a lot of "head," that is, if you
are pumping to a height of more than say, seven or eight feet, or
if you must pull the water (not "push", for in-line pumps
push water fine but don’t pull well) a long distance from
the pond to a skimmer located far away, then these pumps probably
won't work for you.
How About Battery-Operated Fountain Pumps?
Fountain Mountain, Inc. receives many, many calls about battery-operated
pumps. While there are companies who manufacture pumps that can
operate on "A" and "AA" batteries, we have not
found a battery-operated pump that lasts or that is reasonably priced.
For those customers who need battery fountains for wedding centerpieces
(a common request), we suggest you buy as many as possible battery-powered
fountains at a store like Wal-Mart and remove the pump from the
fountain. You get the whole fountain for as good of a price as we
could get you these specialized pumps all by themselves, and we
don’t have to order 500 of them at a time!
What About Solar Pumps?
Fountain Mountain, Inc. also receives many inquiries about solar
pumps. These are okay, but we have decided not to carry them because
of a few reasons. For one, these pumps, like battery-operated
ones, just aren’t so trustworthy; they don’t last
as long as a regular pump. For another, they go on and off constantly
depending on quality of sunlight, passing clouds, etc. unless
you buy one that works on batteries and solar. Then you have to
keep replacing batteries. Also, the ones that work on both solar
and batteries are expensive for the little bit of water they will
pump. Finally, what decided it for us was that some companies
allow credit card charges for all of their products except for
solar pumps. This means to us that the companies are afraid of
too many returns from customers. Eventually, the technology might
be there for us to sell them, but we are not quite ready.
Where is the Pump Made?
Pumps, like anything else, are made all over the world, and we
suggest you buy pumps from someone who will stand by a guarantee
and who has testing programs before marketing their pumps. It
used to be that Asian pumps were quite bad but this is changing.
What matters most is how well the pumps have been engineered and
the materials used in the production. Italy for quite a while
has been the major manufacturer of fountain pumps (think of how
long Italians have had fountains), but Germany, Korea, Taiwan,
and China are making pumps as well. Most American fountain pump
companies (for example, Cal Pumps and Beckett) have their pumps
manufactured overseas. As long as American engineering is used
and the plans are followed, this should not be a problem.
Should my Pump Have a 2-wire plug or a 3-wire plug?
Outdoor pumps should always use a grounded, 3-wire plug. Indoor
fountains sometimes have 2-wire and sometimes 3-wire plugs. For
people wanting a really thin cord, 2-wire pumps provide the more
aesthetic experience. Some retail stores require 3-wire pumps
even for indoor fountains (though, ironically, they might not
for aquarium pumps), and these thicker cords can be hidden by
plants, stones, or other decorations. All pumps must be connected
to a GFI outlet for safety.
Why do pumps burn out so often?
95% of the time the customer has let the pumps get hot by running
them dry. Most fountain pumps are water-cooled and once the fountain
is dry they burn up. Usually there is nothing you can do about
this other than to buy a new pump. Also, pumps are supposed to
be cleaned every so often by opening up the impeller case on the
fountain pump. Follow the manufacturer’s directions.