Backyard Aquaponics
A place to discuss aquaponics

On this topic I would have to agree I would add on a 10m cord a decent warranty and the ability to buy spare parts.

I don't think it is
as you yourself suggest further down in your post:


a manufacturer that takes care of efficiency will almost automatically build reliable pumps

the main problem is the price: good pumps cost more
the return on investment can be calculated, this is easy,

then each has to calculate for themselves the if the extra price is worth the extra insurance
as no two situations can be compared

to give an example:
I used to have a team of 10 engineers working for me installing cleaning systems in the food industry
At first I bought only quality equipment

but this got either frequently dropped from ladders or stolen on the wharf
it didn't last long

later I bought the cheapest possible
I made a profit on this apparently wrong decision

this shows how a wrong choice can be a good decision

frank

THe L/Whr requires that you compare similar head heights. I would be silly to take a result from a pump delivering to 3m and a result from one delivering to .1m and then try and make a comparison between the two.

Why go to the bother of calculating that table since when I've finished I have to compare my result to other pumps anyway to get a meaningful result. Comparing my pump to theoretical impossibilities does me no good what so ever. I allready know that what ever pump I choose it will perform poorly compared with what is theoretically possible. What I want to know is of the pumps which are available to me which option is the best.

I don't care which option is the best relative to what is theoretically possible.

Horses for courses Frank
Tradies now are starting to buy junk tools ie use it till it stops then throw it away. If its mine I like quality and reliability.

absolutely, Sleepe
if it is for me I spend some more
the example I gave shows a different situation

In Europe we now have the advantage that manufacturers are by law required to give two (2!) years of guarantee

this will in time push junk out of the market
(many consumers do not know about this law yet)
shows that laws are good for something

frank

My point was that "energy efficiency" was not an important part of their decision process in picking a pump.

With aquaponics there are other factors. Buying a cheap pump knowing that it will only last a short period of time is not a good idea, even if it might end up generally more efficient in monetary terms to be buying a new pump on a semi regular basis, you don't want to run the risk of losing fish to a pump failure. It's not like using a cheap drill and having a spare one ready for when the first one blows.

Guarantees can vary depending on the manufacturer. Often suppliers will tell you that it is not a warranty claim because of xxxxxxxxxxxxxxx, and they have many reasons, I know, I have heard many reasons why they won't warranty an item. The client has abused it, we checked it and believe the pump has run dry, we believe the pump has had sand in it, the pump has been run on its side, the pump has been run continuously and it's not warrantied for that, the pump had some plant matter wrapped around the shaft, the list goes on and on.... And it all Leaves you without a pump, even though there was a lengthy warranty period.

Joel The way i see it is no mater what pump you use you get 4 pumps the same and run them in different ap systems some are bound to fail for what ever reason one things for shore your system and mine will still be running for the next few years like they have for the last 4 and 2years respectivley while some are still trying to work out whats the best pump

my point was that in their search for a truly reliable ump,
they were bound to fall on one that has good efficiency characteristics too

this TMHO is not a coincidence
as the numbers confirm

same works the other way:
if you look for an energy efficient pump, you are bound to find a reliable one

frank

I think this threads purpose was clearly stated when it was begun....

Perhaps discussion of "energy efficiency" should be directed to the other "efficiency" thread and this one left clean for it's intended purpose...

I agree.
but then the title of this thread should be changed to "pumps - reliable ones and unreliable ones"
in which case I will not partake in it
as to me and undoubtedly to many others the most reliable pump cannot be considered as good if it wastes 95% energy
and if here are other choices (as I have shown there to be)

TMHO "good" pumps means they have to be AND "reliable" AND "efficient"
else they are not "good", only "reliable"

frank

A reliable pump is a "good pump".... an unreliable pump is a "bad pump"....

Cost, both of purchase and energy usage... can be determined by the user.... by people listing their data and experiences here... and weighing the reliability factor in consideration when selecting a pump....

Given that "efficiency" seems to be measurable by different methods... often with differing results... then discusssion can more suitably take place in the relevant thread(s)....

I think "Good" ones and "Bad" ones sums it up sufficiently....

F&F 2 years and 4 years is just 'running in', unless they were pre-used

+1........it sums it up perfectly and simply without having to go into depth, the efficient/inefficient use of english

Yea mine ran non stop for over 10 before ap