New study on propeller pumps has some interesting findings! EcoTech vs Tunze?

[revhtree]

Some of you may have read the article that was released today over at Advanced Aquarist that shows the output flow of propeller pumps and compares them.

Couple things to note is that the EcoTech Vortech rated better that the manufacturer claim and the Tunze Pumps rated lower.

Check it out and let's discuss it here in this thread.
Advanced Aquarist's Online Magazine

Here are the tested pumps and their advertised flow ratings as well as what the rate actual was.


Info from: Advanced Aquarist
PUMP-----------------------Advertised Flow-------------Actual Flow
Aqueon 2400--------------------2400------------------------2744
Coralife CP 2900----------------2900------------------------2437.2
Ecotech Marine MP-10----------1575------------------------2460.3
Ecotech Marine MP-40----------3200------------------------3781.2
Ecotech Marine MP-60----------7500------------------------8509.8
Hydor Koralia 5------------------1650------------------------2597.59
Hydor Koralia 6------------------2200------------------------2205.6
Hydor Koralia 7------------------2700------------------------2659.1
Hydor Koralia 8------------------3250------------------------3188.3
Maxijet 1200----------------------295-------------------------405.7
Tunze 6105----------------------3434------------------------2358.2
Tunze 6205----------------------5811------------------------3234
Tunze 6305----------------------7925------------------------3597.3

 

[revhtree]

Tunze who's pump under-performed released this statement:

Where did we get our flow numbers?

We derived our flow numbers in two ways, by a test termed a “bag test” and by theoretical calculations. The bag test is just as simple as it sounds, a collapsed bag is placed over the end of the pump and inflated by the pump with water, the time to fill the bag is measured and the flow is calculated. This method has definite limitations, it places backpressure on the pump, and it cannot be used on larger pumps given the limits of bag volume and reliable timing. For all pumps a theoretical calculation is made based on propeller surface area and rotation frequency.

Our bag test results are consistent (within + or – 10%) with theoretical results on the pump models 6015, 6025, 6045, 6055, 6065 and 6085. This led us to rely on theoretical numbers. The biggest pump that a bag test can be performed on is the 6105 and the inaccuracy of flow numbers on the 6105 has a different origin than 6205 and 6305 inaccuracies. The 6205 and 6305 flow numbers were only based on theoretical calculations. The 6105, when released, was near specified flow and was bag tested with a result of 90% of theoretical, however, later modifications to reduce noise relied on theoretical flow numbers and flow was lost to these modifications. On models 6205 and 6305 the fundamental issue is that the theoretical flow cannot be reached due to overly constricted intake and output.
Going Forward

Over the next 6 months we will perform numerous tests aimed at improving our pumps. We believe pump volume alone does not equal effective flow, the ability to direct that flow is also important. In much the same way as the light available from a bulb means little if it cannot be properly directed into the aquarium, the flow rate at a pump is not as important if there is not sufficient flow at the corals.. We have since purchased two flow meters, one uses comparable sonic technology and the other uses a propeller akin to a common wind gauge and while we have found that using the comparable meter and methodology our results are the same. We have also found the propeller based meter gives divergent data, this data indicates that our more forceful targeted flow draws in current as the distance from the pump increases and that our total flow produced may be well higher than the flow of the pump itself. 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.

 

[Saltwatercoral2]

i kinda thought that the vortechs produced more flow then advertised. good stuff!

 

[-Logzor]

i kinda thought that the vortechs produced more flow then advertised. good stuff!

Same, I knew the MP60 had to be more than 7500, that thing is insane.

 

[florida reef]

WOW tunze! So it's not even like it was a minimal discrepancy, they claimed almost DOUBLE the actual max flow rate. Get out of town...

 

[m and m]

I want to strap two MP60's to the back of my canoe to see if it will move me. Any one have two to donate?

 

[Saltwatercoral2]

tunze vs vortech, ill take vortech everytime, tunze selling stuff and claiming its rated something its not! hahah.

 

[revhtree]

Both EcoTech and Tunze are great companies and I am anxious to see what Tunze does to correct this problem. I know it will be a good step forward for them and the consumer. EcoTech just out performed themselves. HA!

 

[Troylee]

Wow that's crazy!!! I knew those mp60's were nasty man they sucked half my fish up..hehe that's a great article and great results seems everyone was spot on besides tunze not a huge issue there still great pumps regardless...

 

[PR_Reefers]

lol... tunze are waaay over advertised!... I always knew vortechs has no match!

 

[soccerbag]

I just finished reading the whole article. While most of it was over my head (lol) the conclusions didn't surprise me. Tunze is a good company, I agree, but their claims have not been true. I think they will have to completely redesign their pumps to compete moving forward. I have seen around 100 threads over the past few years asking Tunze vs. Ecotech. At least we have something to point these people to when they are on the fence. Looks like a good old-fashioned, scientific butt whipping!

Roger's response was good. But the Tunze numbers / claims will always be questioned now which is unfortunate. Not the best day for Tunze...

 

[Aquaph8]

Very interesting, now I want someone to do an article on repair rates of all these pumps. I hear so many post of people having to send their pumps in to be repaired all the time.

 

[gooch]

I'm a Tunzer for life. Never been let down by the products or customer service. By the response to me it looks like they took the information and are going to work the problem. Had they had no intention to rectify the error then maybe it would be a problem. I love the stream pumps I have. I have been using Tunze products for about ten years.

 

[dougers31]

Looks like if you buy the korillia 6 instead of the 5 you're a sucker

 

[-Logzor]

Looks like if you buy the korillia 6 instead of the 5 you're a sucker

Mysterious results like this makes me wonder.

Did koralia screw up or was there an issue with the test?

 

[WrasseSandwich]

Interesting, glad to see vortechs are underrated, surprised by the tunze

 

[PR_Reefers]

Tunze admits their wrong!!

Tunze issues statement regarding the results of the propeller pump flow article

 

[mtordie]

My take away and 2 cents. Tunze = Overpriced, False adverted, ineffcient compared to competitors, but they seem to be reliable. You can get 2 Koralia 8's for the price of the Tunze 6105's and they both have similar performance but the koralia is more energy efficient. You can use one and save money on the electric bill and if it died replace it with the other. Although I've never had a reliability problem with a Koralia. Regardless if you chose this route you would still ahead of the game and saving money. And make no mistake this type of marketing and pulling the wool over the eyes of customers is a game to businesses. Seems Tunze has connected the market on this and charged a premium for a inferior product. Glad I never bought into it.

Honestly I don't think you really can't even compare the Vortechs in this type of comparison even though it shines.... The controller and abilities of the Vortechs blow everything away. Literally. The software algorithm for wave generation must be a nasty piece of code and as a result the vortechs are not just a propeller pump like the rest in the group. Never had a reliability problem with mine but If I did I'd still by another one before the others. Its more bang for the buck in flow and in wave making abilities.

 

[Tabasco1]

While it is surprising and definately not the best day for Tunze, I am impressed that they responded that they intend to fix the issue and the thanks and recognition to those who conducted the study at the end was pretty classy. It will be interesting to see how they come back from this.

In the mean time. Bet you will be able to get a heck of deal on a Tunze right now!

 

[-Logzor]

Here is a post from Roger that I found, I think he is right on the money:

Please read the entire release- we are fixing it, there will be a solution, but we need time to find the solution. Within 6 months, we will be at or very near the stated flow.

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.