Did Tunze ever fix its pumps to make the advertised flow rates?

[SpencerG]

I came across this thread from 2011, which unfortunately devolved into Tunze-bashing leading to its being locked:
http://www.reefcentral.com/forums/sh....php?t=2043590

The gist is the flow numbers advertised didn't match up to actual performance, though flow measurement lacks a consistent measurement standard. Tunze steadfastly promised a fix that would be made available to current owners, either free or for a price. Was a solution ever devised? If so, is it available?

I'm just curious. For the record, I own several Tunze products, am very satisfied with all of them, and will continue to buy them. I was simply struck by Tunze's response and am wondering if they followed through.

[sirreal63]

They offered a wider shroud and upped the voltage, if you have one of these pumps 6105 or larger IIRC, get with Roger to see what they are doing currently.

OT, I loved Doug's reply before he locked that thread.

[E.intheC]

Just to add.. not only was the "study" conducted by two people, one of them being an Ecotech employee/intern, the smaller Tunze pumps like the 6045, 6055, etc never had the problem to begin with. The 6095 wasn't even sold yet.

[Tang Salad]

Wrong post.

[spicytuna]

When I saw the thread awhile back, the first thought that came to mind is: there is no standard for circulation pump testing and every company has there own way of rating there circulating pumps

Just from my own un biased opinion, running an mp10 and a 6095, both running at 100% side by side, the tunze is WAY stronger then the mp10, yet it has a much lower flow rating

Tunze also stated flow ratings were calculated before a few modifications were made to the stream pumps

Either way, technically, there is no way to give an exact flow rating on a circulation pump. Where your powerhead sits in the tank, the size and surrounding water volume of the tank have a lot to do with the amount of water moved.

If you'd like to test how strong your vortech is, try running it on a take with the maximum glass thickness, then try it on a tank with the minimum glass thickness. You will notice a huge difference in performance.

Just my 2 cents

IBTL

[Craig Borowski]

There isn't much to add to this topic that hasn't already been addressed, but Jack is correct that higher voltage jumpers and wide-flow propellor housings were offered to increase measured flow rates on the models which the article called in to question.

The bottom line is that GPH can be an incomplete metric for measuring a powerhead's ability to move water in an aquarium. To look solely at GPH would be the same as saying that a 400W MH with no reflector "puts out more light and is therefore superior" to a 250W MH with a reflector.

Another way of looking at this is to imagine a single gallon of water in an aquarium. Measure it and count it as a single GPH as it leaves a pump. But within inches of leaving that pump it is drawn back into the pump and tallied again as it leaves. It adds to the pump's GPH when measured from that specific distance, but since it only traveled a few inches, it is a useless GPH as far as the aquarium is concerned. GPH do not tell the whole picture because flow quality is as important as flow quantity.

For my last words on this I'll just add that the topic of water flow in the ocean and within an aquarium is a fascinating one. It is also very complex. It lies at the heart of what Tunze has been doing for the last fifty-three years and it's one which we will continue to pay very close attention to. I encourage anyone with interest to read the above link and others. There is a very large number of firsthand accounts that will help you form a more accurate, more complete, more useful picture.

[Fleem]

Originally Posted by E.intheC

Just to add.. not only was the "study" conducted by two people, one of them being an Ecotech employee/intern, the smaller Tunze pumps like the 6045, 6055, etc never had the problem to begin with. The 6095 wasn't even sold yet.

Not directly related, as the tests involved different Tunze pump models than discussed in this and that other thread, but an apparently independent, Italian group also reported that the Tunze Silence pumps they examined produced lower flow rates than advertised. (They published their findings in a blog post, so obviously not peer-reviewed.) I've been looking at info on various pumps over the past week, and happened to come across this info as I was looking for info on Tunze Silence and Eheims the other day.

[Allmost]

Originally Posted by Craig Borowski

There isn't much to add to this topic that hasn't already been addressed, but Jack is correct that higher voltage jumpers and wide-flow propellor housings were offered to increase measured flow rates on the models which the article called in to question.

The bottom line is that GPH can be an incomplete metric for measuring a powerhead's ability to move water in an aquarium. To look solely at GPH would be the same as saying that a 400W MH with no reflector "puts out more light and is therefore superior" to a 250W MH with a reflector.

Another way of looking at this is to imagine a single gallon of water in an aquarium. Measure it and count it as a single GPH as it leaves a pump. But within inches of leaving that pump it is drawn back into the pump and tallied again as it leaves. It adds to the pump's GPH when measured from that specific distance, but since it only traveled a few inches, it is a useless GPH as far as the aquarium is concerned. GPH do not tell the whole picture because flow quality is as important as flow quantity.

For my last words on this I'll just add that the topic of water flow in the ocean and within an aquarium is a fascinating one. It is also very complex. It lies at the heart of what Tunze has been doing for the last fifty-three years and it's one which we will continue to pay very close attention to. I encourage anyone with interest to read the above link and others. There is a very large number of firsthand accounts that will help you form a more accurate, more complete, more useful picture.

Im an electrical engineer, a professional eng now in Canada, your explanation is good, but the GPH number is wrong as you stated, and wrong info should not be advertised that is the bottom line ! sad to see such a good company like Tunze not being able to be honest about their flow, or not being able to do the correct calculations, when others like korallia even did the right thing ! I like to think Tunze is a better company than korallia, but not seeing proof for it.

Tunze would have been better off, saying on their product, that pump X is Comparable to a pump with xxxxGPH flow. not that it produces xxx GPH of flow

unfortunately, the tunze ownders in canada got no "fix", hence the large second hand tunze market up here.

[oldimpala]

Allmost-

Although it's not an ideal situation; and a person who has owned and used a large amount of Tunze products, your angle seems a bit accusatory. I'd venture to bet, based on how they run their business, it wasn't an intentional overstatement, and movement of any fluid can be measured multiple ways.

A perfect example is the movement of electricity through a conductor; being an engineer can you tell me precisely how much current a 12 Ga Wire can move? Of course you can't; there are tons of variables, voltage, temperature, wire composition, stranded or solid, and so on...

Or how many CFM does my cylinder head flow on my car? Or why does my bathroom exhaust fan not move 110 CFM when it's colder out, as it does warm?

Should I yell at Piper because my Archer burns more fuel than they told me it should, or cruises 5kt slower than spec sometimes, at indicated power?

Should I yell at Wonder if my bread molds a day before my "Best if Used By" date?

Should I be angry at Ben & Jerry's when my Cherry Garcia doesn't seem to have enough cherries?

Fortunately there are standards for some of these (life and death importance) ratings. Fluid dynamics especially is tricky to model; and you more than anyone should be somewhat familiar with that from your Gen-Ed engineering classes.

There aren't standards for testing powerheads. So, it's possible, under certain circumstances, Tunze was right. And the nice folks that created the stir at EcoTech are right, too. Or both could be wrong. Or we could all be wrong. Or right. I do find it odd that the largest Tunze competitor singled them out for "missing" the mark. Who honestly can say a MJ1200 is a competitor to a Stream or Vortech?

Similar things work in powerheads. Is it 3000 GPH at the nozzle outlet, an inch away, in FW or SW, with a paddlewheel flow detector, or the "Bag" test, or... All are variables; if you don't know them, especially as an engineer, you shouldn't assume that the tests are nefarious; try asking for clarification, first.

Until then, I'll keep the Streams in my tank because they're silent, reliable, energy efficient, and the one or two problems I've had with them (O-rings, usually left on by yours truly in vinegar baths, that swell) have been quickly rectified.

It's been a far better track record than the competition's propeller pumps in my tank, without naming names.

If the flow ratings are off by 100 GPH, or 500 GPH, my corals, fish, and I are happy. So, in the end, who cares? Really....

Basically, to anybody above, I'd say get over it... If it's really *that* important to anybody's life, ya'll may want to get out more.

I know that'll annoy some, but really guys. It's a powerhead. In a fishtank. Not neurosurgery.

[James77]

Originally Posted by oldimpala

Allmost-

Although it's not an ideal situation; and a person who has owned and used a large amount of Tunze products, your angle seems a bit accusatory. I'd venture to bet, based on how they run their business, it wasn't an intentional overstatement, and movement of any fluid can be measured multiple ways.

A perfect example is the movement of electricity through a conductor; being an engineer can you tell me precisely how much current a 12 Ga Wire can move? Of course you can't; there are tons of variables, voltage, temperature, wire composition, stranded or solid, and so on...

Or how many CFM does my cylinder head flow on my car? Or why does my bathroom exhaust fan not move 110 CFM when it's colder out, as it does warm?

Should I yell at Piper because my Archer burns more fuel than they told me it should, or cruises 5kt slower than spec sometimes, at indicated power?

Should I yell at Wonder if my bread molds a day before my "Best if Used By" date?

Should I be angry at Ben & Jerry's when my Cherry Garcia doesn't seem to have enough cherries?

Fortunately there are standards for some of these (life and death importance) ratings. Fluid dynamics especially is tricky to model; and you more than anyone should be somewhat familiar with that from your Gen-Ed engineering classes.

There aren't standards for testing powerheads. So, it's possible, under certain circumstances, Tunze was right. And the nice folks that created the stir at EcoTech are right, too. Or both could be wrong. Or we could all be wrong. Or right. I do find it odd that the largest Tunze competitor singled them out for "missing" the mark. Who honestly can say a MJ1200 is a competitor to a Stream or Vortech?

Similar things work in powerheads. Is it 3000 GPH at the nozzle outlet, an inch away, in FW or SW, with a paddlewheel flow detector, or the "Bag" test, or... All are variables; if you don't know them, especially as an engineer, you shouldn't assume that the tests are nefarious; try asking for clarification, first.

Until then, I'll keep the Streams in my tank because they're silent, reliable, energy efficient, and the one or two problems I've had with them (O-rings, usually left on by yours truly in vinegar baths, that swell) have been quickly rectified.

It's been a far better track record than the competition's propeller pumps in my tank, without naming names.

If the flow ratings are off by 100 GPH, or 500 GPH, my corals, fish, and I are happy. So, in the end, who cares? Really....

Basically, to anybody above, I'd say get over it... If it's really *that* important to anybody's life, ya'll may want to get out more.

I know that'll annoy some, but really guys. It's a powerhead. In a fishtank. Not neurosurgery.

Allmost is one of about 3 people here that always take the opportunity to pounce on Tunze over the single test that was done. No amount of argument from the "other side", including a person that actually worked with the equipment used to test them, seems to matter. The member familiar with the testing equipment used- his screen name is Hydrologist- said there was a +/- 30% margin of error. Give Tunze -30 and MP40 +30, and you can see how it can be potentially very faulty. I'm not saying it was either number, but its amazing how people take the results of one test as gospel.

I have owned both power heads. I prefer Tunze for several reasons. Every other reason aside and concentrating on flow only...... I would not have ever guessed the large difference in flow that the test claims between both what Tunze stated and the MP40. I actually would have thought the MP40 was weaker from the performance seen in the tank, and that is before they upped the voltage.

But again, it has been argued to death and will never change......To anyone else, I can only say that you will never be disappointed with the flow from a Tunze, I don't care how accurate the flow rating is. Ask Roger or Craig which would suit your tank the best.

[SpencerG]

Good to hear Tunze followed through on their word. That is part of what sets them apart in this hobby and really adds value.

[aandfsoccr04]

I agree with the sentiment above. The tunzes are amazing pumps that far exceeded my expectations and are silent no matter how high or low they are turned up.

[biecacka]

+1 to Jim's statement. I love my Tunze In fact I had 2 6105's and a wavebox. I traded the wavebox for a vortech mp40 and in my opinion it was nowhere near as powerful or effective as my 6105's.......so I traded that bad boy to another guy for......wait.....wait....another 6105

Corey

[r-balljunkie]

Originally Posted by Allmost

Im an electrical engineer, a professional eng now in Canada, your explanation is good, but the GPH number is wrong as you stated, and wrong info should not be advertised that is the bottom line ! sad to see such a good company like Tunze not being able to be honest about their flow, or not being able to do the correct calculations, when others like korallia even did the right thing ! I like to think Tunze is a better company than korallia, but not seeing proof for it.

Tunze would have been better off, saying on their product, that pump X is Comparable to a pump with xxxxGPH flow. not that it produces xxx GPH of flow

unfortunately, the tunze ownders in canada got no "fix", hence the large second hand tunze market up here.

im a mechanical engineer, with a fair background in pumping and fluid dynamics....sorry, no real way to quantify or standardize these tests. methods and means for employing tests vary. you change a single factor and you could come up with subjective numbers in either direction.

Aside from Fanboy camps digging in and taking sides, its fair to say Tunze products deliver.

[Krazy]

Either way!

I think TUNZE pumps are the BEST PERIOD!

Nuff said'

[Allmost]

Originally Posted by r-balljunkie

im a mechanical engineer, with a fair background in pumping and fluid dynamics....sorry, no real way to quantify or standardize these tests. methods and means for employing tests vary. you change a single factor and you could come up with subjective numbers in either direction.

Aside from Fanboy camps digging in and taking sides, its fair to say Tunze products deliver.

well, to be honest, I own mostly Tunze stuff .... from osmolators, to 2 6105, and I set up a new 60 G tank just this month, with 4 tunze pumps and return so please .... lets have a friendly discussion about a product ...

will you please explain to me how every pump in market passes the test Except Tunze ? are they different then every other pump there is out there ? does the error margin only apply to tunze and nothing else ?

why didnt tunze say the tests were wrong ? instead Roger said we will fix it, and started shipping out breakers wih higher voltage !! is that their way of admitting to it ? ... that to me shows "guilty" .

Tunze reps continue to say GPH number doesnt matter, and that its about quality of flow ... I agree ! but why not put that on the box rather than putting a wrong GPH number up there ?

you know what I mean ? if you work in eng. as a professional, then you know that these "mistakes" are not good to make ! sure .... their "mis-calculations" on GPH number could be wrong and it wont kill me .... but ethics are ethics ! if fan companies started testing their equipment tomorrow, and found out Brand XX was not being honest about the flow ... can company XX's CEO come out and say " Come on ppl .... its not like its gonna kill anyone, its just a fan, let it go"

if you think that the fan company can come out and say that and be accepted by public, then sure, Same goes with Tunze for you, but not for me ....

like the other guy who brought in live rock illegally and got cought and every one was mad at him on here ! i was too ! but could he come out and say " come on ... it didnt kill anyone, get out more often if you care about live rock so much" ....

but again, not knocking the product itself, I like the tunze pumps, but I do not like the hyped up GPH numbers, in order to put them in the same market range as some other products ... they could have simply said on their box "GPH is not important, the quality of flow is important, this pump can be COMPARED TO a pump generating XXX GPH ... " then it would have all been fine ...

[oldimpala]

Originally Posted by Allmost

will you please explain to me how every pump in market passes the test Except Tunze ? are they different then every other pump there is out there ? does the error margin only apply to tunze and nothing else ?

You know what I mean ? if you work in eng. as a professional, then you know that these "mistakes" are not good to make ! sure .... their "mis-calculations" on GPH number could be wrong and it wont kill me .... but ethics are ethics ! if fan companies started testing their equipment tomorrow, and found out Brand XX was not being honest about the flow ... can company XX's CEO come out and say " Come on ppl .... its not like its gonna kill anyone, its just a fan, let it go"

if you think that the fan company can come out and say that and be accepted by public, then sure, Same goes with Tunze for you, but not for me ....

A few bullets to reply:

1: I don't mean to sound like a conspiracy theorist, but it is funny *who* did the test, and *who* passed and failed. It would be like GM doing a test on a Ford, and saying "it's not as good."

Do I think that sending out revised jumpers was an admission of guilt? Not really; you want to overdrive your 6105's? Run 'em hotter. Whatever. It's a PWM controlled DC motor, go nuts.... You're an EE, ask Roger what max spec is, and build a controller. They did it to quell people like you, who still aren't satisfied. If they did nothing, and said "we stand by our numbers, and these guys are insane..." Would you have felt better, or hammered on them for "doing nothing in the face of an obvious problem..."

My question is, in light of these results.... How would you have handled it? Going back in time, and changing the specs isn't an answer, btw. In this exact situation, what would you have done differently?

2. We already know you're an engineer. I'm not; I'm in Marketing for a large telecom.
Here's the deal though; why is it that I can tell you how/why fluid dynamics can be presented differently, and come out with vastly different results, yet you can't grasp it?

In your world, model electrical current across a conductor. Then change some variables. Electrons follow similar models to liquids. Change 1 teeny-tiny variable, tell me if it changes. The IEEE has written hundreds of papers, and some open source software on it.

If you're bored, come to Buffalo, I'll even pick you up at @ CYTZ, I'll fire up a few fluid dynamics programs I have from work (Autodesk CFD is the most used, here) to model airflow through ProAc duct cavities, and change air temperature by 5 degrees; I'll show you what the difference in CFM is. If they used different temp water in Germany versus this test (Read: Density) it can affect the outcomes.

Water works similar to air with densities. If you need sources; I can share them with you.

3. Fan companies disclaim the heck out of their argument, can cite pressure drops in inches of mercury, and show CFM at nozzle under lab specs. Basically, they reveal their test components, environment, and results. Just like Tunze did. That's how they win.
They also tell you in the real world you don't get 110 CFM out of your fan; you know.. If you put pipe on it, or a vent cap outside your bathroom vent fan. What they do tell you is it's bigger and moves more air than a 90 CFM, but a little less than the 130 CFM.

So, should I call Broan today, and call them liars? No; they explained their measurements, and how they achieved published specs. Just like Tunze did.

So, yeah. Get over it.

My question is... Again. What would the right response have been; same time, same scenario, same options available to you. No time-machine to change published specs.

Being a guy who's department frequently interacts with national PR, I'd be really interested in your response.

[r-balljunkie]

Originally Posted by Allmost

well, to be honest, I own mostly Tunze stuff .... from osmolators, to 2 6105, and I set up a new 60 G tank just this month, with 4 tunze pumps and return so please .... lets have a friendly discussion about a product ...

will you please explain to me how every pump in market passes the test Except Tunze ? are they different then every other pump there is out there ? does the error margin only apply to tunze and nothing else ?

why didnt tunze say the tests were wrong ? instead Roger said we will fix it, and started shipping out breakers wih higher voltage !! is that their way of admitting to it ? ... that to me shows "guilty" .

Tunze reps continue to say GPH number doesnt matter, and that its about quality of flow ... I agree ! but why not put that on the box rather than putting a wrong GPH number up there ?

you know what I mean ? if you work in eng. as a professional, then you know that these "mistakes" are not good to make ! sure .... their "mis-calculations" on GPH number could be wrong and it wont kill me .... but ethics are ethics ! if fan companies started testing their equipment tomorrow, and found out Brand XX was not being honest about the flow ... can company XX's CEO come out and say " Come on ppl .... its not like its gonna kill anyone, its just a fan, let it go"

if you think that the fan company can come out and say that and be accepted by public, then sure, Same goes with Tunze for you, but not for me ....

like the other guy who brought in live rock illegally and got cought and every one was mad at him on here ! i was too ! but could he come out and say " come on ... it didnt kill anyone, get out more often if you care about live rock so much" ....

but again, not knocking the product itself, I like the tunze pumps, but I do not like the hyped up GPH numbers, in order to put them in the same market range as some other products ... they could have simply said on their box "GPH is not important, the quality of flow is important, this pump can be COMPARED TO a pump generating XXX GPH ... " then it would have all been fine ...

That’s easy. Company A ran a test one way, company B ran it another.

These aren’t really pumps, they are moreso like blowers.
Pumps have an inlet and an outlet.
Water in one end, out the other. You define the media (fluid property type) and pipe sizes then extrapolate your curve based on GPM and pressures.
For blowers and industrial fans, you would follow ISO standard ISO 5801:2007
For centrifugals ISO 5198:1987
I’ve spent countless hours on pump test stands (big stuff +2000 hp).
Trust me, you can fudge numbers if you really wanted to.
c

[James77]

Originally Posted by Allmost

but I do not like the hyped up GPH numbers, in order to put them in the same market range as some other products ... they could have simply said on their box "GPH is not important, the quality of flow is important, this pump can be COMPARED TO a pump generating XXX GPH ... " then it would have all been fine ...

Hyped up according to one test!!!

Was the test right? Maybe. But we have one person- hydrologist-- that hade stated that HE HIMSELF had worked with the testing equipment and there was a large margin of error.

Maybe the flow from Tunzes IS different. I have had both the Tunze 6105 and Mp40 in my tank, side by side. The flow from the Tunze was more powerful and more effective. More water, debris, detritus moved than did with the Mp40, all over the tank. I'm sorry but the GPH reading from that test equipment have to be flawed for the Tunze just what I see with my own two eyeballs. Maybe they should have found a way to test further out with all the pumps, who knows if the Tunze produces an educator effect? I was just baffled how people took that one single test to immediately side against Tunze.

I would love to see someone with access to equipment or even different types of equipment do a 100% independent test of the pumps and just see what the results are.

Edit: I'll just add that I am not blindly defending Tunze. I truly could care less what the flow is from the pumps, they work best for me due mostly to noise. BUT, I can say that something seems seriously out of whack to get results that far off from their advertised numbers and so far off from the Vortech when I have seen these 2 pumps in action at the same time. There was on single test done using equipment that we have someone familiar with (Hydrologist) saying has a wide margin of error done at a competitors facility(Ecotech). I really don't know how anyone could take that as a 100% acceptable test. At the very most it should raise a flag with further looking into.

[tkeracer619]

All of that aside, tunze never fixed the 6305 and they redesigned their entire lineup around that study. Tunze hconfirmed the results in more ways then one regardless of how many people tried to discredit it. Good pumps but they got caught with their pants down and were not real quick to pull them up. Still see a bit too much if you ask me. Suprised they didn't get sued tbh.

[SpencerG]

Based on the large percentage of customers who appear to be more than satisfied with the pumps, I don't think there would be many plaintiffs for a lawsuit.

[E.intheC]

Originally Posted by SpencerG

Based on the large percentage of customers who appear to be more than satisfied with the pumps, I don't think there would be many plaintiffs for a lawsuit.

Also, no one was complaining about a lack of flow before this "study" came out anyway. GPH is a difficult thing to accurately quantify, especially for the average hobbiest. If you're happy with the flow a pump puts out, why would you change your mind if someone came out and said "your pump has fewer GPH than you thought previously"?

Tunze should have done more to fix the issues quickly with the 6305 pumps, but they did a good job with the lower models, IMO. And as a percentage, I'm sure there are many more 6105 customers than 6305.

I know this is only slightly related, but why are skimmer companies (including Tunze) able to get away with these ridiculous tank ratings? It's so bad that companies have to over estimate their skimmers ability or risk losing market share based on the idea that "every company overrates their skimmers"

[Beenalongtime79]

Wow, way to beat a dead horse. The tunzes perform and deliver more than enough flow.

Cheers,
John

[Beenalongtime79]

A little off topic but how is the wave motion created by the pumps alone using the newer controllers... Tunze multicontroller 7096.

Cheers,
John

[heritage]

Originally Posted by rufio173

A little off topic but how is the wave motion created by the pumps alone using the newer controllers... Tunze multicontroller 7096.

Cheers,
John

Not sure what you mean ?

The 7096 is used in pulse mode down to the fraction of a second. The on rush of water is what creates the wave.

Having owned both the mp10 and 40, all I can say is that I could not get rid of them fast enough.

I'm much happier with my pair of 6095's and 7096 controller. I never had any real success with getting any kind of a wave with the vortec, but I can get a standing 1" wave in under 20 seconds with the tunze.