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pHaestus 11-27-2002 11:57 AM

Common pump P-Q Curves (graph inside)
1 Attachment(s)
I was bored this am, and decided to search the web and dig up P-Q curves for the most common wcer pumps used/sold today. I got the curves from the following places:

Hydor L20 and L30:
Eheim pumps:
Sicce Idra:
Via Aqua 1300:

A note: The Via Aqua 1300 numbers as reported in their table do NOT result in a normal P-Q curve. I suspect that the max head of the the 1300 is much closer to 5 feet than to 6, and that the numbers are not exactly correct. I'used the P-Q curve provided on that page rather than the numbers in the table. It lists max flow of 400 GPH rather than the 370 reported by other vendors.

Another note: I just read representative points off the graphs and then used them to make a crude P-Q curve of my own. They obviously may be off by a few %.

Anyway, here goes:

pHaestus 11-27-2002 12:05 PM

An addendum:

Some of these pumps (Sicce, Via Aqua, Hydor) are typically used submerged but also will work inline. I do not know the exact conditions of the testing; I just reproduced the curves on a single graph.

g.l.amour 11-27-2002 12:27 PM

another one for in the WC encyclopdedia

Albigger 11-27-2002 12:54 PM

nice work, a definate asset. have you been able to find any P-Q curves of the Danner Mag drive pumps? (specifically model 7)? I only found some rough numbers, from which BigBen made a small graph in another thread somewhere.

I was just wondering if you happen to come across any, because I couldn't find that information anywhere else

FRAGN'STIEN 11-27-2002 04:02 PM

Some great info pHaestus, thanks, but shouldn't it read:

flow (GPH) instead of flow(GPM)?

I don't know about anyone else, but my Ehiem 1048 will not produce 9600 GPH;) :D

pHaestus 11-27-2002 04:35 PM

yes it's true. Should read GPH not GPM. I set everything up in Excel so I could also do SI; then didn't pay enough attention to the units in graph. I don't think I can edit that graph as I added it as an attachment. I'll make a new graph and attach again shortly.

Still haven't found Danner numbers yet.

pHaestus 11-27-2002 05:07 PM

Two birds with one stone
1 Attachment(s)
Found Danner info here:

And added the 250gph (Mag2) and 350GPH (Mag3) to list.

It's getting pretty busy now...

bigdawginva 11-27-2002 05:16 PM

Awesome work. Had no idea the Danner's faired so well. Perhaps an intersecting wattage line as well.

Great work and thank you!

pHaestus 11-27-2002 05:24 PM

It's REALLY hard to know how much variability there might be between pumps. Plus mfgrs sometimes overstate performance (see C/Ws at for more info).

I suspect the Danners pull more watts than the others I seem to recall my model 2 being around 25W.

Joe 11-27-2002 05:36 PM

Wait!!! you mean there is something mis stated or incorrect on the web?!?! NOOO! Someone needs to get on this, I am calling the FBI right now since obviously some hax0r has changed the numbers on them... cause no one would ever lie on a [W]ebsite.


pHaestus 11-27-2002 05:39 PM

Well there is just SO much potential variability. Someone told me that they had their heatsinks tested by several different labs, and that they came back with C/W from 0.2 to 0.6. And those were all professional testing labs.

bigdawginva 11-27-2002 05:44 PM

My apologies if I hit a nerve.

I assumed all the pump manufacturers (and others) embellished approximately the same.

pHaestus 11-27-2002 05:48 PM

Well they may. It is a reasonably straightforward measurement I would think, and so perhaps the numbers are all right on.

But I think people are (reasonably) skittish about mfgr performance claims. Industrial pumps undoubtedly have standards for such, and I would expect the curves for the mfgrs who also make higher end pumps to be pretty reliable. Not so sure about the "hobby pump" makers though.

BillA 11-27-2002 06:57 PM

nice compendium pHaestus

some unquantified opinion based on bits and pieces:

from a European mfgr, pretty much on
from US mfgr for industrial (small pump) apps, pretty much on
from US mfgr for 'hobby' market, very variable (some correct, others smoke)
from Japan, spot on
from China, whatever they chose to say

Joe 11-27-2002 08:08 PM

Wow I didnt know accuracy knew country borders... I thought it was more a per company thing :)

BillA 11-27-2002 08:47 PM

no, its a fraud penalty thing

the EU will levy fines,

psychofunk 02-23-2003 07:31 PM

1 Attachment(s)
I can't remember who or where other then in these forums but this graph was posted. He said he ran the water through 1/2" ID tube to come up with it. What if you guys did the same thing for each pump and started a database.

Les 02-23-2003 11:11 PM


Originally posted by psychofunk
I can't remember who or where other then in these forums but this graph was posted.
Reduced to a edit.

sevisehda 07-02-2003 08:12 PM

I need to get a new pump as my old one is dieing(or at least making plenty of noise). The cheapest pump I've seen is a VIA AQUA for 18.49. But the stores min online purchase is 30$ so sshould I either get 2 VIA AQUA 1300's for 37$ or get a Danner Mag3 for 36$.

Also I know theroretically 2 pumps in series is double the pressure and 2 in parallel is double the flow. But in the REAL world more double the pressure actually means double the possible head so flow would actually increase. And for parallel doubleing the flow would actually create more resistance which would decrease flow. Not even taking into account that its not actually 1 + 1 = 2 but6 slightly less. The previsous period is confusing I know but so is the math behind it. Does anyone have any formulas or rules of thumb for calculating flow using multiple pumps? Thanks for any help.

bigben2k 07-02-2003 08:39 PM

You could simply spend $30 on the Johnson pump ;) .

Otherwise, I believe you'll find about 85% of the total pressure that you expected.

pHaestus 09-03-2003 03:15 PM

update with new swiftech pump

Click for larger image.

I should note I am using 3.785L/gallon and 0.3048m/foot in all corrections (should you want the numbers for conversion).

Does anyone know how that sites like this:
generate graphs on the fly from text data? It would be really sweet to be able to graph all of these P-Q curves on the fly rather than on this single graph that is getting pretty busy.

Les 09-03-2003 06:38 PM


pHaestus 09-03-2003 08:17 PM

Les: It's from the mfgr specs and is as good as their word. Bill has some pretty good evidence that the Eheim P-Q curves are a bit optimistic. Of course he's also a mfgr now too and subject to the same suspicions right? I personally think the Via Aqua numbers are bogus for sure (as mentioned above).

But hey we have to start somewhere right? Of interest to me is the apparent dominance of a relatively inexpensive pump (Danner Mag3) and the high head performance of Swiftech's new entry.

Got KarmA? 10-01-2003 09:41 PM

hmm, no iwaki's or eheim 1060 ...

beggars can't be chosers I guess ;)

pHaestus 10-09-2003 11:19 AM

Graph updated today to reflect newer P-Q curves for MCP600 from Bill.

I can't include many more pumps without ending up with a graph noone can read...

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