Another new product we spied at MACNA this year was the Tunze 6095, a brand new addition to the Nanostream lineup. At first glance, the 6095 may appear to be just a widemouth version of the 6055, but upon closer inspection we noticed a couple of unique features this water pump brings to the table. For starters, the output of the pump has a noticeable downward bend at the bottom, toward the front of the housing. When discussing this feature with Roger of Tunze USA, he indicated that this was done to allow for more water to be drawn in and pushed out over a wider but shorter area, creating a much broader and more gentle flow than the other models. The other major difference in the 6095 from its predecessors is the almost complete lack of a propeller guard at the opening of the pump. Instead, the 6095 has small fin-like projections that induces a spin on the exiting water flow. The openings on the other pumps acts more like a tail fin on an airplane to stabilize the water flow, whereas this new design causes more turbulence. The advertised flow rates for the controllable 6095 are 528 to 2,510 gallons per hour at a power consumption of 5-21watts. The retail price is just a shade over $260 and the pump is scheduled to be release very soon.

A photo of the pump’s opening can be seen below.

As if the water pump niche of the aquarium industry needed anymore drama, the magnifying glass moves now onto a patent by EcoTech Marine. According to Eric over on Glassbox Design, it would appear that the patent on the popular VorTech pump is being “re-examined”. The request for the re-examination was filed by a Houston-based law firm, but it remains unclear as to who the firm is working for. Regardless of who is behind the request, it is one that EcoTech will have to take seriously, which we’re sure they will. Another feature Eric highlights in his article is a specific patent filed by Mag-Life several months prior to the VorTech patent. The Allis patent owned by Mag-Life does in fact cover their use of magnetically coupled motor that is used in a filtration system, and according to the re-examination claim, the VorTech uses every patented feature of the Mag-Life pump.

We’re not 100% sure how this will play out, but it could potentially go very badly for EcoTech Marine. We’ll keep an eye on this issue as it unfolds and we wanted to thank Eric for sharing his discovery over on his blog Glassbox Design.

Responding to the results of the Advanced Aquarist Flow Study and the reactions by folks in the aquarium community, Tunze has announced a couple of pump upgrades that will be available later this year. The first of these upgrades will be available to the Tunze Stream 2 model 6105 water pump, which is their most popular model. It will consist of a 24V jumper and an upgrade in the pump housing. The jumper replaces the 18V jumper currently in the power supply of the 6105 and instantly increases flow rates by 800 gallons per hour. Of course, this also means a slight bump in power consumption to 30watts, and noise levels are expected to increase as well, but only very slightly. To better handle the increase in flow, the Tunze 6205.130 housing is also available as an upgrade, and it will easily fit right onto the 6105 assembly giving the pump widened flow patterns. Both the power supply jumper and housing upgrades will be made available to existing Tunze 6105 users by November or December of this year, and the price is expected to be around $30.

So what does these upgrades mean for the future line of the Tunze Stream 2 pumps?

According to Tunze, the 6105 will start to include all of these parts straight out of the box. This means future users will get a factory pump as they are sold today, but with the added upgrades in the box as well. Hobbyists will be able to choose between 12V, 18V, and 24V jumpers, as well as two different pump shrouds for either narrow long flow or wide short flow. These included options will cause a slight bump in the retail price of the Tunze 6105 by $30. Tunze also promises that these or at least similar upgrades will be made available to other pumps in their lineup as well.

D-D The Aquarium Solution recently added some newwater pumps to their site called the H2Ocean Flow Pump. This new line of pumps feature a seamless coated permanent magnet and synchronous motors that yield efficient performance that doesn’t take a toll on moving parts and is quiet. Each pump is surrounded in a thermal protective plastic housing that is ideal for both freshwater and saltwater applications. A flow control device is built right into the pump outlet that allows the water flow to be adjusted, and the pump also comes with 1″ and 3/4″ adapters. Three models are currently available. The Ocean-flow 4000 and 5000 pumps can be used externally or in-sump, but the Ocean-flow 2000 model is designed only to be used in submersible applications.

Individual pump specifications can be seen below.

H2Ocean Flow Pump Models and Specifications:

Model: 5000

• Max flow – 5000 l/hr
• Min flow – 1000 l/hr
• Max head – 3.1 m
• Wattage – 82 w
• Price – £99.99 (roughly $165)

Model: 4000

• Max flow – 4200 l/hr
• Min flow – 600 l/hr
• Max head – 3.5 m
• Wattage – 80 w
• Price – £94.99 (roughly $155)

Model: 2000

• Max flow – 2000 l/h
• Min flow – 300 l/hr
• Max head – 2.25 m
• Wattage – 31.5 w
• Price – £39.99 (roughly $65)

The now infamous water flow rate study conducted on various propeller based water pumps by Sanford, Straka, and Joshi that was published in Advanced Aquarist a short time back caused quite a commotion in the aquarium community. The initial goal of the study was only to examine a possible way to accurately measure water flow rates from propeller based water pumps, but the results of the test had a far reaching impact on the aquarium community. The study implied that Tunze pumps significantly underperformed in relation to other water pumps on the market, also missing their advertised flow rates by as much as 56% for their largest model, the Tunze Stream 6305. Tunze was given the data before the results were published, did a little testing of their own, and concluded that the results were accurate for the specific testing equipment and methodologies used to determine the flow rates in the original study. Despite owning up to the results of the study published in Advanced Aquarist, Tunze also expressed doubts in both the method and instrument used to arrive at the flow numbers and set off to perform a test of their own, which is described in detail in the video above.

In the video, multiple Tunze and EcoTech Marine pumps are individually tested in a 150-gallon aquarium using a handful of different methods, though EcoTech’s name is never used. Instead, they are labeled only as “competitor”. Before the testing is demonstrated though, we get an explanation about the different types of water flow, the importance of turbulence and how it affects flow rate measurements, an explanation on Tunze’s more laminar flow, and what test methods are being used in this latest water pump study. The first experiment consists of injecting a dye into the water on the intake side of each pump and watching how far it travels and how quickly it is dispersed. The second test is similar, but instead of injecting dye, an air pump feeds bubbles into the intake of each pump. Both of these tests demonstrate the more laminar water movement produced by the Tunze Stream and nanostream pumps, while also showing how much more turbulent the pumps of the “competitor” are. Because of these differences, the Tunze pumps are shown to push water a far greater distance.

The third test performed by Tunze is accomplished through the use of a RCI Clima AIR 5. It is a propeller-based flow meter that showed slightly different results of the other water flow study, but overall is in agreement with those results. Tunze didn’t use this device to measure flow rates though, but to instead show that the turbulent flow was present and to demonstrate the quality of the flow. They also go on to state that the propeller based flow meters are subject to drag and resistance, and will inherently show lower flow rates.

The last thing we wanted to discuss from this video is the displaying of the unreleased Tunze 6095 nanostream’s flow pattern. The 6095 is compared to a VorTech MP40, and the two pumps look nearly identical on the dye injection test, at least in terms of dye distribution throughout the test aquarium. And this is the type of flow pattern Tunze’s was aiming for with this new pump…something more broad and turbulent while still moving a significant amount of water.

The final conclusion to be drawn from this test and the one published in Advanced Aquarist is that flow rates measured in gallons per hour (or any other velocity for that matter) are essentially useless. Flow measuring methods are not accurate and are influenced by a myriad of factors that have yet to be tested by any company. Water flow is extraordinarily complex, especially when things like rocks, glass, and other stationary objects get in the way and divert the flow. The main goal for any reefkeeper though is to do a visual inspection of how the water flows in their tanks, making sure that detritus is suspended in the water column and the corals are getting enough flow to deliver nutrients and effectively remove metabolic byproducts. In closing, I also want to emphasize that this flow test and the flow study conducted by Sanford, Straka, and Joshi should not be taken at face value. Both studies were performed by people with skin in the game, meaning neither one can be truly objective as the performers of the test are also the manufacturers. That being said, we desperately need independent testing agencies that can measure manufacturers’ claims and give aquarium hobbyists the proper knowledge to make informed choices.

A couple of days ago, Tunze released a long-awaited firmware update to their 7096 Multi-controller, which is used to control certain Tunze Stream water pumps. Responding to the requests of users, the Version 1.1.0.6 update will include a few new features on already exisiting applications. For example, in the “Pulse Only” mode we now see updated “Ramp” and “Random flow” settings.  Under the “Interval” and “Sequential” mode, Tunze has added their “Minimum flow for switched off pumps”. Overall, users have reported this update as being a refinement of currently available controller modes, and indicate that the update works really well.

Descriptions of the new settings below.

According to the Tunze descriptions, the updated “Ramp” function is a time-delayed start where the pump starts out at a low speed and increases over time, but has the added feature of a soft start. Before the update, this setting caused the pump to be somewhat noisy, but the new firmware creates a low-noise gentle start of the pump that users have been praising. The “Random Flow” setting, as its name implies, sets a random alternating pulse frequency from 0.5 to 3 seconds for each pump. The “Minimum Flow For Switched Off Pump” is a setting that is actually found under two different modes, “Interval” and “Sequential”. In Interval mode, the “min. flow for switched off pump” behaves more like the “Interval 2″ setting on the Tunze 7095 Mult-controller. Under the Sequential mode, this setting is one in which the circulation pumps are not switched on and off alternately, but are set variably between a specified maximum and minimum output, with the lowest minimum being 30%.

I apologize if this is a little hard to follow, especially if you’re not already using a Tunze controller or aren’t familiar with their modes.  But the update is completely free to users, and those already using the update appear to be pleased with the new settings.

The water pump flow rate study conducted by Michael Sanford, William Straka and Sanjay Joshi and published on Advanced Aquarist has made a giant splash in the aquarium community. The results were so astounding that most hobbyists had to take a double or even triple take, as they challenged the advertised flow rates of well-known and respected brands, the most affected of which was Tunze. The primary goal of the study was not to call out any particular company on their flow numbers, but to instead find a way to accurately measure flow rates of aquarium pumps without the test equipment creating an environment that caused the pumps to perform under any additional loads such as back pressure. Despite these goals and the achievements of the study, a lot of people are dwelling on the data, and for good reason. According to the data, the Tunze Streams (models 6105, 6205, and 6305) do not have flow rates that compare to their advertised rates. In fact, the numbers are off by as much as 56% for the largest model. Tunze was sent a copy of the results prior to the article being published, and they actually confirmed those results. In lieu of the findings, Tunze has released a public statement explaining how they arrived at their advertised flow rates and what they plan on doing to fix the discrepancies.

The official statement from Tunze can be read below. Additionally, a little information from Roger Vitko of Tunze USA is also provided.

According to Roger Vitko, none of the pump manufacturing companies knew their flow rates prior to the study and all of the companies used the same methods of bag testing and theoretical calculations to arrive at their figures. He goes on to state that the reason the flow rates of the Tunze pumps were so different is due to the intake structure choking the flow. He further explains that just by removing the front cover of the pump, flow rates increase by 20-35%. Because of this, the front cover will be redesigned and will be retrofittable to all existing Tunze Streams for a nominal price. Wrapping up our discussion, Roger told us that Tunze will work to improve water flow and the company will be better for this. Many tests have been performed and new molds have been created, and he expects to see the changes by the end of the year.

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.

We applaud the fact that Tunze is taking responsibility and admitting that their methods of determining flow rates was inaccurate. Tunze is a great company and we love their products and customer service. We have high expectations for future generations of their Stream and Nanostream water pumps and hopefully hobbyists don’t knee-jerk react to the article.

By now I’m sure you’ve read the incredibly in-depth article covering measured flow output of various propeller-based water pumps over on Advanced Aquarist. For those of you who haven’t, here’s a quick rundown. The study was conducted by Michael Sandford, William Straka, and Sanjay Joshi with the main objective being to develop a method to more accurately measure water flows rates of various aquarium propeller pumps. Previous methods of measurement relied heavily on equations based on propeller fin measurements and pump rotational rates to calculate the theoretical flow rate. Additional methods of flow measuring consisted of simple bag-fill tests where, as its name implies, a bag of a certain volume was filled with water from the pump being observed. The testers would note how long it took to fill the bag to volume, and the flow rates were calculated. Understanding the intense complexity of water movement and the issues with commonly used testing methods, the group of researchers set out to develop a newer and more accurate way to measure water pump flow, and the results have been quite surprising.

Tunze Stream Flowrate Testing

Before we get into those surprising results, we must first describe the test and the instruments. A test tank of 350-gallons was set up and the tool used to measure the water flow was a SonTek/YSI 10-MHz ADV (Acoustic Doppler Velocimeter).  This ADV is described as a “proven, accurate solution for high-precision, 3-axis (3D), velocity measurements in a wide variety of settings from the laboratory to the ocean”. It is an instrument used by various well-known colleges in both the lab and field, and is a suitable tool for measuring water flow from pumps as it doesn’t create back pressure or unusual conditions that a pump wouldn’t normally encounter. A strobe tachometer and Kill-A-Watt meter were also used to measure each pump’s rotational speed in RPMs and power consumption, respectively.

Water Pumps Used in Flow Rate Study

Thirteen brand name water pumps were tested, including all of the EcoTech Marine VorTech pumps currently available, multiple Hydor Koralia pumps, and the three most powerful Tunze Streams. The ADV was placed at different points in front of each water pump’s opening, measuring data at 5mm increments along both the vertical and horizontal axes. The results were compiled into a flow profile with each pump, and some of these results have caused quite a bit of stir. Some pumps exceeded their advertised flow rates, while others significantly underperformed. Based on the study, all of the EcoTech Marine VorTech pumps had flow rates that exceeded their advertised rates, as did the Hydor Koralia 5 and the Aqueon 2400. Surprisingly, each of the Tunze pumps were shown to consistently under perform, with the Tunze 6305 producing less than half of its advertised flow rate. What appeared to be an anomaly in the study was the fact that the Hydor Koralia 5 produced more water flow than a Koralia 6, and almost as much as a Koralia 7. No explanation was given for this anomaly.

Water Pump Flow Rates

The results of the test apparently even surprised the testers, as they sent the paper to Tunze prior to publication. Tunze conducted their own tests and apparently confirmed the results of this paper, but there’s no information given as to how they performed the independent test. We assume it was through the same or at least similar methods, but that remains to be seen at this point. Tunze has also released a press statement regarding the results of both studies, which we will discuss in a future article.

As for our opinion of the test, we feel there is a significant conflict of interest, despite the fact that Tunze has agreed to the test results. The reason for the conflict is EcoTech’s donation of the test equipment needed for the study and the fact that the person collecting the date was an EcoTech Marine intern.

“We would like to thank EcoTech Marine for providing the large aquarium and renting the equipment needed for the study. The work was performed under the technical guidance and consultation with Bill Straka and Sanjay Joshi of Penn State University. The data was collected by Mike Sandford during his summer internship at EcoTech Marine.”

I’m not at all trying to imply that EcoTech Marine or Mike Sandford are skewing the data, nor am I questioning the integrity of anyone associated with this test. However, when reading the article, you must keep in mind that the equipment was provided by EcoTech Marine and the results favor their products significantly. The VorTech pumps are great products, and I’ve owned several over the years, but any time you see a company essentially conduct a study of its own products alongside those of the competition and come out on top, you do have to question certain aspects of the study. The Tunze Streams are the single greatest competitor of the VorTech pumps, and to see them come out at the bottom is not only shocking, but turns into a PR nightmare for the company.

My only possible explanation for the significant difference in advertised versus actual flow rates for the Tunze Streams is the fact that they have a tube-like shroud protruding from the front of the pump. The VorTech pumps on the other hand, do not have a tubular shroud, but are instead wide open. On top of that, the Tunze shroud is seemingly longer than those of other pumps on the market, which further restricts flow and depresses water flow numbers. When describing previous and unreliable tests performed on older water pumps, the writers indicated that pumping water through a tube-like apparatus constrained water flow and created back pressure. For this reason, those tests were not accurate for propeller-based water pumps and it may serve as a reason behind the water flow differences in the Tunze pumps. This is of course speculation on our end, but given the design differences of each pump, it could serve as a reasonable explanation. This design may be an Achilles’ heel for Tunze, and a trip to the drawing board may be in order.

In closing, I wanted to again state that I do not doubt the test results or question the intentions of the testers. In fact, I applaud their efforts at expanding the understanding of water flow and the measuring of such parameters. Regardless of that, there is still a conflict of interest and I would honestly like to see more testing done, but this time by a completely disinterested third party. Even if the results were identical and the same equipment used, the study would be more readily accepted by the aquatic community and remove doubts from skeptical readers.

Finally, we have water in our 90-gallon rimless AGE aquarium, and with water comes the need for water flow, a crucially important aspect of any reef aquarium. We got our hands on a pair of Tunze 6055 Nanostreams, a pair of pumps we are greatly impressed with, and wanted to share their un-boxing with the rest of the reef keeping world. The seal on the box was excitedly peeled away, revealing a tiny yet powerful pump and one of the strongest aquarium magnets offered in the hobby. Mating the pump to the magnet is Tunze’s Silence Holder, which uses four rubber feet to prevent pump vibration from creating excess noise, despite the fact that the Nanostreams are already so quiet. The feet slip into the plastic bracket with ease, though they have a tendency of slipping out when adjusting the pump. The correction to this is as simple as reinserting them into the bracket, making sure the lip around the top and bottom of the feet are secured into the brackets. The feet also have a tendency of impeding the adjusting of the pump within the bracket, but this is actually an aspect I favor, as it prevents the pump from coming loose in the holder and pointing in an undesirable direction, for example one that causes a massive sandstorm.

More hands on with the Tunze 6055 after the page break.

Moving on to the pump’s controllability, the pump uses a power supply with adjustable voltage settings. If you don’t want to use a Tunze controller, you can manually adjust the water flow by moving the voltage slider on the underside of the power supply. Of course, the pump will stay at this flow rate until it is manually adjusted again. The voltage is adjustable from 12V to 24V, allowing the 6055 to push water from 264 to 1,453gph. Power consumption also varies with flow rates, starting at a mere 4watts and climbing to only 18watts. The 6055 Nanostream is just one of many Tunze electronically controllable pumps, though it is the only Nanostream that is currently controllable. The 6095 Nanostream will be controllable, but it isn’t scheduled to release until later this year. The flow on the 6045 can be adjust manually through a built-in plastic flow controller located on the underside of the pump, but it’s purely a manual control. To control the 6055, you would need a Tunze 7095 or 7096 multi-controller, or one of Tunze’s single controllers.

The reason we chose the 6055 pump for the aquarium build is not only for its controllability, but the fact that it’s a Tunze product. Tunze makes great pumps that are very reliable and get the job done. Sure, they are more expensive than a lot of other pumps on the market, but given Tunze’s long standing presence in the hobby, excellent customer service, and continual innovation, the decision was quite easy. The hardest part of picking out a pump was selecting the particular Tunze model we wanted to use.

Water pumps and powerheads are great tools to move water in our aquariums. Water flow itself is extremely crucial to aquarium health and stability, so the use of powerheads is almost unavoidable. Water moving devices come in multiple forms, with the most common of those being propeller-based powerheads and externally driven closed-loop systems. The powerheads remain inside the aquarium, sucking in water through an intake and expelling it out of the front. The intake usually has a strainer of some sort, and most newer powerheads draw in water over a large surface area to spread out their suction force. Despite spreading out that force, the pumps can still cause a lot of damage to aquarium inhabitants. Fish that pass too close to the pump can get sucked in, and wandering invertebrates can quickly turn into chopped up remnants of their former selves.

Continue reading below to find out what happened to the anemone pictured above, as well as how to prevent these events from happening.

Case in point, local aquarium hobbyists Tnconcept found out the hard way how deadly a powerhead can be. His rose bubble tip anemone (Entacmaea quadricolor) uprooted itself and wandered right into the intake of a Koralia powerhead. The tentacles of the anemone were sucked into the pump, which quickly shredded them to bits. The tiny anemone bits were floating around the aquarium, which could eventually lead to a tank crash if the proper actions aren’t taken. Fortunately, the hobbyist was able to perform an emergency water change, and chances are the anemone will recover from the injuries.

All this being said, I wouldn’t fear using powerheads in any of my aquariums. They are a cost effective way of moving water and creating turbulent flow. If you are concerned that your livestock might get caught in one of these pumps, you can place foam on the pump’s intake. This will help prevent livestock from getting sucked into the pump, but it will add a little bit of maintenance to your routine as they will need to be cleaned from time to time.

Special thanks to Tnconcept for letting me use this image and sharing this story.