Tunze - False Advertisement?

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tkeracer619

tkeracer619

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As I was drinking my morning coffee getting ready for a long workday in the sun I was browsing through Advanced Aquarist as usual and found a rather interesting article. The study measures actual flow output in GPH along with some other data for many pumps. Some did better then the manufacturer claimed and some didn't do so well. As published in this study Tunze has been advertising their pumps as having roughly 2x the flow then they actually do.

I wonder how Tunze is going to react to this? I mean if I were to pay a premium for a pump (which I have) and got half of what I paid for I would be pretty upset (which I am). I know several people who designed their tanks around tunze to get a specific flow for sps corals and are going to find out soon that they only have half of what they paid for.

Just for comparison if I ordered a sports car and it came with half the engine I surely wouldn't accept it and I am sure the company wouldn't either. In this case return would be the only option but I am not sure what Tunze who has tons of these pumps out there is going to be able to do to make their customers happy.

Any thoughts?

Link to said article
http://www.advancedaquarist.com/201...ider&utm_medium=slider&utm_campaign=clickthru
 
if the study says everyone rates gph wrong, then you've probably never seen the correct gph, meaning you would have no means for comparison.
Not saying you don't have great flow, saying you may not have "rated" flow....
 
According to the addendum at the end of the article "Tunze conducted its own independent tests on the Tunze pumps and have confirmed our results". It further went on to say that the author did not feel Tunze was trying to mislead, however their results were based on "their misguided faith in theoretical calculations that often do not translate well into real world application and use"
 
Couple of points to consider:

This study was done at Ecotech's offices with funding from them. Not saying there is bias but it's definitely something to consider.

Also, in terms of real world results, it's hard to argue with results using either Tunze or Vortecs.

While the article seems thorough, data can always be massaged to support a viewpoint, and it's doubtful that more then a handful of people reading the article can truly say that the data and methods are truly correct (I know I can't :) )
 
roni said:
Couple of points to consider:

This study was done at Ecotech's offices with funding from them. Not saying there is bias but it's definitely something to consider.

Also, in terms of real world results, it's hard to argue with results using either Tunze or Vortecs.

While the article seems thorough, data can always be massaged to support a viewpoint, and it's doubtful that more then a handful of people reading the article can truly say that the data and methods are truly correct (I know I can't :) )
Click to expand...

Roni, two things to keep in mind.
  1. Unless the author lied Tunze repeated the test and got the same results.
  2. Even if the Tunze fall far short of their rated output they still have a very respectful output so the test results would not indicate bad real world results.
 
Orcrone said:
Roni, two things to keep in mind.
  1. Unless the author lied Tunze repeated the test and got the same results.
  2. Even if the Tunze fall far short of their rated output they still have a very respectful output so the test results would not indicate bad real world results.
Click to expand...

It might not indicate bad real world results but a 6305 puts out 3600gph and costs $710 without a controller. Thats seems like a pretty poor cost to flow ratio
 
spieszak said:
if the study says everyone rates gph wrong, then you've probably never seen the correct gph, meaning you would have no means for comparison.
Not saying you don't have great flow, saying you may not have "rated" flow....
Click to expand...

My post was just talking about their rated flow for the MP40 which they show higher then the 6205. I had 2 40's on my old tank and switched to 6205's in anticipation of a new tank. The 6205's were clearly more flow at full blast then the 40's, I couldn't even run them turned all the way up, like I could with the 40's. I don't know, the study just seems at odds with my personal experience.
 
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Which powerhead to buy/use is an emotional issue (it seems). Each person should purchase whichever they find to be right for them. Taking shots at the other side accomplishes nothing really and certainly does not convert a "believer" on one side to a "believer" on the other side.
 
It looks like Tunze - while acknowledging that the study's flow measurements are correct - is working on fixing the problem and believes it can be done with propellers and housing changes.

Tunze is obviously an upstanding and conscientious company that makes great products that people love using. I think the upshot of this study should be the recognition that measuring flow is extremely complex.


Here's Tunze's response:
For that matter, the flow is pretty much all there, we tested fixing the shaft on one end and using no propeller housing at all, the flow goes up 20-35% depending on the model. The issue is restriction of the flow by the housing and not some major defect, it is solvable, but it requires redesigning the propeller housing and some tweaks to the propellers. This really is not a huge catastrophe, it is a set back, it stings, it sucks it happened, but we will come out better for this. Imagine if the flow you had from our pumps which you were already satisfied with increased 25-45%? Before this article, I have not seen one single complaint, not one single post, PM or email that the flow does not seem to be what we say, how many posts are there about how much stronger someones 6105 feels compared to there MP-40 or 6055 compared to an MP-10. I think if you step back and just look at this rationally, even go to a store that may have both running in displays, you will see that gph only is a very small part of the story of flow.
Click to expand...

Use of a different methodology may very well give the opposite results, but this does not dispute the results of this study, it will only show that flow is complex and has numerous aspects which we are only beginning to understand. At this point we conclude that the study is correct for the flow produced by the actual pump itself and we will improve the pumps in a retrofittable manner, though this will take time as new parts must be designed and produced. Improvements will be based on increasing intake surface and reducing output restrictions on models 6205 and 6305 and increasing rotational speed for 6105. We would like to thank Sanjay Joshi, Bill Straka and Michael Sandford for performing this study, graciously informing us of the results and giving input on proposed solutions. We believe it is a step forward in uncovering many of the mysteries of high volume, low pressure flow which until recently was nearly impossible to quantify.
Click to expand...

http://www.reefcentral.com/forums/showthread.php?t=2043590
 
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I am glade to see my Hydor Koralia 6 are what Hydor say they are in flow. It makes me feel like I was not taken for in the flow. But Hydor says 10w but tested at over 21w. that is not good!
 
snorvich said:
Speaking as a Vortech user?
Click to expand...

I prefer vortech because I think they are a better pump but have used almost all of the pumps featured in the article. I recently purchased a tunze for my gfs tank because she wouldn't let me drill a hole in the wall so I could use a mp40. Its been 3 weeks and it is going back to the store this weekend when I get home. She agreed on the hole now :)
 
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