Multiple pumps for failure protection?

[Scott Evans]

In a recent posting here, someone had lost their pump, and was wondering
what needed to be done to keep their fish safe until a replacement could
be found/installed. That got me thinking (never a good thing, but I
digress) a bit about how to minimize the short-term impact of a pump
failure. Going under the assumption that it takes a certain amount of
power to pump a given quantity of water, would it make more sense to
have multiple smaller pumps hooked up in parallel (with appropriate
back-flow check valves) rather than a single large pump? It shouldn't
take any more power to pump the water; the only additional cost would
be the initial plumbing and pump costs. It might be a worthwhile
tradeoff for peace-of-mind to put out a little more money upfront to
make sure that a pump failure won't take down a whole pond ecosystem.

Comments?

Scott

[Anne Lurie]

Not much of a comment, except to say:

Oh, man, how my father would have loved newsgroups with questions like this,
sigh...... He was an engineer, we had a house on Lake Erie, and a cottage
on Georgian Bay........ he used to get the monthly(?) reports from the Army
Corps of Engineers about water levels on the Great Lakes. And, I swear,
only my dad could get excited when he talked about "acre feet" (the amount
of water necessary to cover one acre with one foot of water).

Through in a question about pumps in parallel, and he would have been in his
element, sliderule & all!



And then's the question that occurred to me when I read an earlier thread
(very embarrassing not to know the answer, as I'm sure I should know it):
"Does a pump have to work harder to move water that's 6 feet under the
surface than water that's 2 feet under the surface"?

Anne Lurie
Raleigh, NC







"Scott Evans" > wrote in message
...[i]
> In a recent posting here, someone had lost their pump, and was wondering
> what needed to be done to keep their fish safe until a replacement could
> be found/installed. That got me thinking (never a good thing, but I
> digress) a bit about how to minimize the short-term impact of a pump
> failure. Going under the assumption that it takes a certain amount of
> power to pump a given quantity of water, would it make more sense to
> have multiple smaller pumps hooked up in parallel (with appropriate
> back-flow check valves) rather than a single large pump? It shouldn't
> take any more power to pump the water; the only additional cost would
> be the initial plumbing and pump costs. It might be a worthwhile
> tradeoff for peace-of-mind to put out a little more money upfront to
> make sure that a pump failure won't take down a whole pond ecosystem.
>
> Comments?
>
> Scott

[mad]

i keep thinking that my dad would have loved computers. when i was a kid we
had fancy radios, transistor radios, a shortwave radio, a movie camera, an
early hand-held calculator, the first TV on our block with a 100 ft tall
antenna, and a CDR rotor to turn it. our car had every gadget known to
detroit on it. yes, he would have loved home computers.
mad
--
You don't stop laughing because you grow old, you grow old
because you stop laughing.

> From: "Anne Lurie" >
> Organization: Road Runner - NC
> Newsgroups: rec.ponds
> Date: Tue, 26 Aug 2003 23:25:22 GMT
> Subject: Re: Multiple pumps for failure protection?
>
> Not much of a comment, except to say:
>
> Oh, man, how my father would have loved newsgroups with questions like this,
> sigh...... He was an engineer, we had a house on Lake Erie, and a cottage
> on Georgian Bay........ he used to get the monthly(?) reports from the Army
> Corps of Engineers about water levels on the Great Lakes. And, I swear,
> only my dad could get excited when he talked about "acre feet" (the amount
> of water necessary to cover one acre with one foot of water).
>
> Through in a question about pumps in parallel, and he would have been in his
> element, sliderule & all!
>
>
>
> And then's the question that occurred to me when I read an earlier thread
> (very embarrassing not to know the answer, as I'm sure I should know it):
> "Does a pump have to work harder to move water that's 6 feet under the
> surface than water that's 2 feet under the surface"?
>
> Anne Lurie
> Raleigh, NC
>
>
>
>
>
>
>
> "Scott Evans" > wrote in message
> ...[i]
>> In a recent posting here, someone had lost their pump, and was wondering
>> what needed to be done to keep their fish safe until a replacement could
>> be found/installed. That got me thinking (never a good thing, but I
>> digress) a bit about how to minimize the short-term impact of a pump
>> failure. Going under the assumption that it takes a certain amount of
>> power to pump a given quantity of water, would it make more sense to
>> have multiple smaller pumps hooked up in parallel (with appropriate
>> back-flow check valves) rather than a single large pump? It shouldn't
>> take any more power to pump the water; the only additional cost would
>> be the initial plumbing and pump costs. It might be a worthwhile
>> tradeoff for peace-of-mind to put out a little more money upfront to
>> make sure that a pump failure won't take down a whole pond ecosystem.
>>
>> Comments?
>>
>> Scott
>
>



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[joe]

Scott Evans wrote:

> would it make more sense to
> have multiple smaller pumps hooked up in parallel (with appropriate
> back-flow check valves) rather than a single large pump?


I think that might be over complicated. I solved the problem by having my
main pump and a back up of about the same oomph. The difference is that my
main pump is a) more expensive because b) it is way more energy efficient.
My back up is just cheap because it only has to work long enough to repair
my main pump.

Joe



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[joe]

Anne Lurie wrote:

> "Does a pump have to work harder to move water that's 6 feet under the
> surface than water that's 2 feet under the surface"?

Nope. Head is from the surface.


Joe



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[RichToyBox]

Scott,

The redundancy of parallel pumps is good design, and if you are trying to
move certain amounts of water, it is cheaper on the electric bill as well.
If you want to move 8000 gallons per hour with a Sequence pump, you have to
step up to the high head, read as high energy consuming pumps, whereas you
can get by with two smaller low head pumps using much less energy. If one
goes out, you still have half the flow through the filter, and over the
waterfall. Aquadyne filters say it is better to have two filters with two
pumps than to have only one large system.
--
RichToyBox
http://www.geocities.com/richtoybox/pondintro.html


"Scott Evans" > wrote in message
...
> In a recent posting here, someone had lost their pump, and was wondering
> what needed to be done to keep their fish safe until a replacement could
> be found/installed. That got me thinking (never a good thing, but I
> digress) a bit about how to minimize the short-term impact of a pump
> failure. Going under the assumption that it takes a certain amount of
> power to pump a given quantity of water, would it make more sense to
> have multiple smaller pumps hooked up in parallel (with appropriate
> back-flow check valves) rather than a single large pump? It shouldn't
> take any more power to pump the water; the only additional cost would
> be the initial plumbing and pump costs. It might be a worthwhile
> tradeoff for peace-of-mind to put out a little more money upfront to
> make sure that a pump failure won't take down a whole pond ecosystem.
>
> Comments?
>
> Scott

[Karen Mullen]

In article >, "Anne Lurie"
> writes:

>
>Through in a question about pumps in parallel, and he would have been in his
>element, sliderule & all!

sounds like my dad - sliderule and all, a mechanical engineer figuring things
out til the day he died.

Karen
Zone 5
Ashland, OH
http://hometown.aol.com/kmam1/MyPond/MyPond.html
My Art Studio at
http://members.aol.com/kmmstudios/K.M.Studios/K.M.Studios.html
for email remove the extra extention

[Lee Brouillet]

There is a school of thought referred to as R.A.I.P., or Redundant Arrays of
Inexpensive Pumps. RTB explained it nicely above; Joe also has a very good
idea. Many of us start off with pumps that were easily "findable", like the
Little Giants or Beckett pumps. But these are inefficient
operating-cost-wise. It's a good idea to do as Joe suggests: replace it
with an efficient pump, and place the other in storage as a back-up. It's
also nice to have another pump to run a quarantine or hospital tank . . .

Lee

"Scott Evans" > wrote in message
...
> In a recent posting here, someone had lost their pump, and was wondering
> what needed to be done to keep their fish safe until a replacement could
> be found/installed. That got me thinking (never a good thing, but I
> digress) a bit about how to minimize the short-term impact of a pump
> failure. Going under the assumption that it takes a certain amount of
> power to pump a given quantity of water, would it make more sense to
> have multiple smaller pumps hooked up in parallel (with appropriate
> back-flow check valves) rather than a single large pump? It shouldn't
> take any more power to pump the water; the only additional cost would
> be the initial plumbing and pump costs. It might be a worthwhile
> tradeoff for peace-of-mind to put out a little more money upfront to
> make sure that a pump failure won't take down a whole pond ecosystem.
>
> Comments?
>
> Scott

[Andrew Burgess]

Scott Evans wrote:

> would it make more sense to
> have multiple smaller pumps hooked up in parallel (with appropriate
> back-flow check valves) rather than a single large pump?

I like it. Even having the second pump off but plumbed in and ready to
take over would be nice. Bonus points for automatic switchover...

[Andrew Burgess]

PlainBill > writes:

>I am of the opinion that one large, properly designed pump would cost
>less to purchase and operate than several smaller pumps,

Could be.

>particularly
>when you consider the flow losses due to the plumbing associated with
>multiple pumps (either each pump must have it's own filter, or each
>pump must have a check valve to prevent backflow in the event it
>fails).

You can make the flow losses identical by adjusting pipe sizes so I
don't think it's a factor.

>He described hooking the thing up one evening, turning the main pump
>off, then checking the pond every hour. Unfortunately he fell asleep,
>only waking up after the main pump had been off more than 8 hours.
>He was rather relieved to find all his koi were still doing well, with
>no signs of any shortage of oxygen.

Its encouraging. He proved that it works for 8 hours for his
fish load, pond volume, temperature and initial oxygen level.