Harlequinmania

Wow didnt know he had a website until now lol...

Click through to see the images. Thursday, July 14, 2011 Scripps scientists part of research team studying cascading effects on ecosystems Scripps Institution of Oceanography / University of California, San Diego The decline of large predators and other "apex consumers" at the top of the food chain has disrupted ecosystems all over the planet, according to a review of recent findings conducted by an international team of scientists and published in the July 15 issue of Science. The study, which included Jeremy Jackson and Stuart Sandin of Scripps Institution of Oceanography at UC San Diego, looked at research on a wide range of terrestrial, freshwater and marine ecosystems and concluded that "the loss of apex consumers is arguably humankind's most pervasive influence on the natural world." According to first author James Estes, a professor of ecology and evolutionary biology at UC Santa Cruz, large animals were once ubiquitous across the globe, and they shaped the structure and dynamics of ecosystems. Their decline, largely caused by humans through hunting and habitat fragmentation, has had far-reaching and often surprising consequences, including changes in vegetation, wildfire frequency, infectious diseases, invasive species, water quality and nutrient cycles. The decline of apex consumers has been most pronounced among the big predators, such as wolves and lions on land, whales and sharks in the oceans and large fish in freshwater ecosystems. But there have also been dramatic declines in populations of many large herbivores, such as elephants and bison. The loss of apex consumers from an ecosystem triggers an ecological phenomenon known as a "trophic cascade," a chain of effects moving down through lower levels of the food web. Sandin's contribution to the study focused on the importance of sharks in coral reef ecosystems. For the past several years, Sandin and his colleagues have explored a chain of islands in the Central Pacific Ocean that feature virtually pristine, undisturbed reefs but also reefs adjacent to populated islands and subject to the effects of pollution and fishing. As documented in the Science study, uninhabited Jarvis Island features a healthy, thriving reef ecosystem with a robust shark population. Neighboring Kiritimati, or Christmas Island, however, with a population of 5,000 people and an active fishery, is absent of sharks and now features an ecosystem dominated by small fishes and overrun by algae. A healthy coral reef ecosystem with sharks off Jarvis Island (left) and a reef off nearby Kiritimati Island (right) with an active fishery and overrun by algae. Photos: Brian Zgliczynski (left) and Jennifer Smith (right). "Practically and ethically, we cannot conduct large experiments to investigate the effects of predator removal," said Sandin. "But in the Line Islands we can rely on a natural experiment to follow what happens when sharks are removed. The abundance of prey changes, the way the energy flows through the ecosystem changes and even the way nutrients are cycled is altered. The importance of this paper is its recognition that predator removal is a global phenomenon, affecting reefs and almost every other ecosystem." In a separate study recently published in the Public Library of Science (PLoS) ONE journal, Sandin and his colleagues began probing the details and mechanisms of how coral reef ecosystems change without the presence of sharks. Comparing unfished Palmyra to heavily fished Christmas Island, Sandin and his coauthors found that the ecology of prey fish changed dramatically in the relative absence of predators. On the reefs of Christmas, the removal of sharks and other large predators leads to an increase in the longevity of prey fish, an alteration in their patterns of growth and ultimately the creation of a wholly new structure for the "predator-lite" coral reef food web, the study showed. "Predators have a huge structuring influence," said Sandin. "When you remove them you change the biology, which is typically profound and complex. And in many cases it's not necessarily predictable." "The top-down effects of apex consumers in an ecosystem are fundamentally important, but it is a complicated phenomenon," Estes said. "They have diverse and powerful effects on the ways ecosystems work, and the loss of these large animals has widespread implications." Estes and his coauthors cite a wide range of examples in their review, including the following: • The decimation of wolves in Yellowstone National Park led to over-browsing of aspen and willows by elk, and restoration of wolves has allowed the vegetation to recover. • The reduction of lions and leopards in parts of Africa has led to population outbreaks and changes in behavior of olive baboons, increasing their contact with people and causing higher rates of intestinal parasites in both people and baboons. • A rinderpest epidemic decimated the populations of wildebeest and other ungulates in the Serengeti, resulting in more woody vegetation and increased extent and frequency of wildfires prior to rinderpest eradication in the 1960s. • Dramatic changes in coastal ecosystems have followed the collapse and recovery of sea otter populations; sea otters maintain coastal kelp forests by controlling populations of kelp-grazing sea urchins. • The decimation of sharks in an estuarine ecosystem caused an outbreak of cow-nosed rays and the collapse of shellfish populations. Despite these and other well-known examples, the extent to which ecosystems are shaped by such interactions has not been widely appreciated. "There's been a tendency to see it as idiosyncratic and specific to particular species and ecosystems," Estes said. One reason for this is that the top-down effects of apex predators are difficult to observe and study. "These interactions are invisible unless there is some perturbation that reveals them," Estes said. "With these large animals, it's impossible to do the kinds of experiments that would be needed to show their effects, so the evidence has been acquired as a result of natural changes and long-term records." The absence of sharks can alter the growth patterns of red snapper (right) and other reef fish. Estes has been studying coastal ecosystems in the North Pacific for several decades, doing pioneering work on the ecological roles of sea otters and killer whales. In 2008, he and coauthor John Terborgh of Duke University organized a conference on trophic cascades, which brought together scientists studying a wide range of ecosystems. The recognition that similar top-down effects have been observed in many different systems was a catalyst for the new paper. The Science study's findings have profound implications for conservation. "To the extent that conservation aims toward restoring functional ecosystems, the reestablishment of large animals and their ecological effects is fundamental," Estes said. "This has huge implications for the scale at which conservation can be done. You can't restore large apex consumers on an acre of land. These animals roam over large areas, so it's going to require large-scale approaches." The Science paper's coauthors include 24 scientists from various institutions in six countries. Support for the study was provided by the Institute for Ocean Conservation Science, Defenders of Wildlife, White Oak Plantation, U.S. National Science Foundation, Natural Sciences and Engineering Research Council of Canada and NordForsk. About Scripps Institution of Oceanography Scripps Institution of Oceanography at University of California, San Diego, is one of the oldest, largest and most important centers for global science research and education in the world. Now in its second century of discovery, the scientific scope of the institution has grown to include biological, physical, chemical, geological, geophysical and atmospheric studies of the earth as a system. Hundreds of research programs covering a wide range of scientific areas are under way today in 65 countries. The institution has a staff of about 1,400, and annual expenditures of approximately $170 million from federal, state and private sources. Scripps operates robotic networks, and one of the largest U.S. academic fleets with four oceanographic research ships and one research platform for worldwide exploration. Birch Aquarium at Scripps serves as the interpretive center of the institution and showcases Scripps research and a diverse array of marine life through exhibits and programming for more than 415,000 visitors each year. Learn more at scripps.ucsd.edu. View the full article

Click through to see the images. Currently, Taiwanese fisherman are already prohibited from discarding shark bodies overboard and are required to bring them back ashore. Taiwan is the first and only Asian nation to have any anti-shark-fin legislation on the books. However, conservationist have criticized this law as too lax and open to loopholes. A new law, which will take effect early 2012, will prohibit the removal of fins aboard fishing vessels; Sharks must be brought into port whole. According to Taiwan's Fisheries Agency chief James Sha, "Any violators may be fined, barred from leaving ports, have their catches confiscated or even have their fishing boat licenses revoked, depending on how seriously they contravene the measures." While this is a most welcomed step in the right direction, it is unfortunately a small drop in the bucket. China's growing prosperity has increased demand for shark fin. China's lax environmental laws pose the greatest threat to sharks. View the full article

Click through to see the images. Currently, Taiwanese fisherman are already prohibited from discarding shark bodies overboard and are required to bring them back ashore. Taiwan is the first and only Asian nation to have any anti-shark-fin legislation on the books. However, conservationist have criticized this law as too lax and open to loopholes. A new law, which will take effect early 2012, will prohibit the removal of fins aboard fishing vessels; Sharks must be brought into port whole. According to Taiwan's Fisheries Agency chief James Sha, "Any violators may be fined, barred from leaving ports, have their catches confiscated or even have their fishing boat licenses revoked, depending on how seriously they contravene the measures." While this is a most welcomed step in the right direction, it is unfortunately a small drop in the bucket. China's growing prosperity has increased demand for shark fin. China's lax environmental laws pose the greatest threat to sharks. View the full article

Click through to see the images. Currently, Taiwanese fisherman are already prohibited from discarding shark bodies overboard and are required to bring them back ashore. Taiwan is the first and only Asian nation to have any anti-shark-fin legislation on the books. However, conservationist have criticized this law as too lax and open to loopholes. A new law, which will take effect early 2012, will prohibit the removal of fins aboard fishing vessels; Sharks must be brought into port whole. According to Taiwan's Fisheries Agency chief James Sha, "Any violators may be fined, barred from leaving ports, have their catches confiscated or even have their fishing boat licenses revoked, depending on how seriously they contravene the measures." While this is a most welcomed step in the right direction, it is unfortunately a small drop in the bucket. China's growing prosperity has increased demand for shark fin. China's lax environmental laws pose the greatest threat to sharks. View the full article

Click through to see the images. The text below was provided by Scott Gebhart of The Alternative Reef. The Alternative Reef is a supplier of quality ceramic coral propagation products. While driving back to Green Bay Wisconsin from MACNA Orlando last year, my wife Kristine and I were mulling over ideas for MACNA Des Moines. Being this is as close as MACNA has been to our location for some time we decided we wanted to do something special this year. You may or may not know much about The Alternative Reef. But we are a small family business that focuses on coral propagation products and hand made ceramic structures. Some time this year we will make our 1,000,000 coral propagation product. When I started The Alternative Reef I never imagined we would progress so far so fast. It is amazing to see the changes that have happened to this hobby over a very short time. Coral propagation and conservation has become a very important part of the hobby. The Alternative Reef is proud to be a part of it. About two years ago we started making larger drop in structures and pillars. It is my hope that one day our structures are considered an environmentally friendly ALTERNATIVE to liverock. Many customers had lots of questions for us at the show. The most asked question was how do the structures would look over time? With help from my friends at Reefs Aquatics, The local saltwater shop in Green Bay. We decided to set up an aquarium and let it grow in. We would take some progress shots and then bring the aquarium to MACNA to show everyone what it looks like over the first few months. The aquarium was put on display at Reefs Aquatics for anyone that wanted to see it and the progress. At MACNA Des Moines we will be donating the 93 gallon Marineland Cube Aquarium. We wanted to give this aquarium to a school but not just any school. This aquarium will be donated to the Smouse Opportunity School. Smouse Opportunity School is a school for special needs students. Why did this school get selected? My wife Kristine and I are proud parents of two special needs children. Actually both are young adults now. My kids, Josh and Megan, play an important part in The Alternative Reef and both have benefited from being a part of the Reef Community. When they were younger we put a small aquarium in one of the classrooms they were in. We saw how well the kids in that class took ownership of the aquarium and how attentive they were. The teacher was able to use it as a learning tool. Every time I would come to do work on the aquarium the kids would all come around and watch and ask all kinds of questions. It was a great experience and we were so happy to do that for the kids. It is our hope the kids, staff and visitors to Smouse Opportunity School enjoy this aquarium for years to come. I hope it is used as a learning tool and it helps to expand the dreams and enhance their lives as much as the hobby has enhanced ours. We have a build thread on Reef2Reef in our sponsor forum. We also are updating similar threads on Captive Reefs, 3Reef.com and World Wide Reefers. The threads also include some of the other vendors that are helping us out with the build: Reef’s Aquatics, Tunze USA, ATB USA, Exotic Frags US, The Filter Guys and a Jim’s Reef. Their generous involvement has made the quality of this aquarium donation even better. Here is the build thread link. http://www.reef2reef.com/forums/alternative-reef/50203-what-were-doing-macna-2011-a-4.html View the full article

Welcome to the club. Sooner or later when you get to know more about this hobby, you may begin to realize that a more complete system with sump tank / protein skimmer, chiller and wave maker ect would be more appropriated for a marine tank setup. A simple tank with a canister filter may still work on a small tank with very little Bio-load and constant water change to keep the parameter in check. However, you would not be able to keep more delicate fish / coral in the longer run, and maybe the amount of money you spend to re-stock your live stock may as well pay for the equipment in the longer run. At the present moment, you might want to consider better filter media like Bacteria King or Bio home with a simple hang on protein skimmer to aid in better water filtration.

According to a new study, 28 percent of cod products in Ireland are mislabeled, as compared to 7 percent in the UK. Using a DNA barcoding technique (COI barcoding gene), scientists from Ireland genetically identified 226 cod products purchased from supermarkets, fishmongers and take-away outlets across Ireland (131) and the UK (95), and compared the results against the product labels. View the full article

The decline of large predators and other "apex consumers" at the top of the food chain has disrupted ecosystems all over the planet, according to a review of recent findings conducted by an international team of scientists. The study looked at a wide range of terrestrial, freshwater, and marine ecosystems and concluded that "the loss of apex consumers is arguably humankind's most pervasive influence on the natural world." View the full article

The enormous decline of large, apex predators and "consumers" ranging from wolves to lions, sharks and sea otters may represent the most powerful impacts humans have ever had on Earth's ecosystems, a group of 24 researchers say. The decline of such species around the world is much greater than previously understood and now affects many other ecological processes through what scientists call "trophic cascades," in which the loss of "top down" predation severely disrupts many other plant and animal species. View the full article

A new study concludes that the decline of large predators and herbivores in all regions of the world is causing substantial changes to Earth's terrestrial, freshwater, and marine ecosystems. The paper claims that the loss of apex consumers from ecosystems "may be humankind's most pervasive influence on nature." View the full article

The decline of large predators and other "apex consumers" at the top of the food chain has disrupted ecosystems all over the planet, according to a review of recent findings conducted by an international team of scientists. The study looked at a wide range of terrestrial, freshwater, and marine ecosystems and concluded that "the loss of apex consumers is arguably humankind's most pervasive influence on the natural world." View the full article

Researchers have identified a protein that can direct stem cells to become either new heart muscle or blood vessels. The research, which was carried out in zebrafish, offers insight into how it might be possible one day to generate tissues to repair the human heart after damage inflicted by a heart attack. View the full article

Click through to see the images. </h3><h3> As a restaurant </h3><h3> The top side is no slouch either! via My Modern Met blog (thanks leftovers!) View the full article

Click through to see the images. </h3><h3> As a restaurant </h3><h3> The top side is no slouch either! via My Modern Met blog (thanks leftovers!) View the full article

Ocean acidification, a consequence of climate change, could weaken the shells of California mussels and diminish their body mass, with serious implications for coastal ecosystems. View the full article

Depending on the size which you get, Aragonaite sand is more expensive but it will help to stabilize the water PH in the tank.

Thanks for sharing, too bad this light is not available locally yet . Is there a LFS in Pattaya ?

Click through to see the images. Tunze Press Release July 13, 2011 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. In response to Advanced Aquarist article, "Experimental Comparison of Measured Flow Output of Aquarium Propeller Pumps" (http://www.advancedaquarist.com/2011/7/aafeature) View the full article

If genetically modified Atlantic salmon were to escape from captivity they could succeed in breeding and passing their genes into the wild, researchers have found. Their research explores the potential reproductive implications of GM salmon as they are considered for commercial farming. View the full article

If genetically modified Atlantic salmon were to escape from captivity they could succeed in breeding and passing their genes into the wild, researchers have found. Their research explores the potential reproductive implications of GM salmon as they are considered for commercial farming. View the full article

Exotic marine species, including giant seaweeds, are spreading fast, with harmful effects on native species, and are increasingly affecting the biodiversity of the Mediterranean seabed. Some native species, such as sea urchins (Paracentrotus lividus), can fight off this invasion, but only during its early stages, or when seaweed densities are very low. View the full article

Click through to see the images. Abstract The purpose of this study was to investigate a method to more accurately determine the output flows of several aquarium propeller pumps. To complete this investigation, a test setup was constructed in a 350 gallon aquarium tank using a Sontek 10-MHz Acoustic Doppler Velocimeter for data acquisition. The velocity profile of the pump exit flow was measured at a distance of one diameter downstream from the output of the pumps and used to determine the volume flow rate output. The results of this investigation reveals that there can be large variability between the manufacturer's advertised flow rates for propeller driven pumps and the flow rates measured by this method. The results suggest that a standardized approach to measuring flow should be created to better enable manufacturers to more accurately advertise the correct flow rates so that consumers can choose the appropriate pump for their aquarium. Flow in the Aquarium Sufficient water movement in aquariums is known to be an important component for animal health and long term success. In general, most reef hobbyist attempt to maximize the water movement within their aquarium (flow rate) using pumps, power heads, or wave devices while minimizing the maximum velocity of the water "hitting" sessile animals. This prevents shearing off of tissue and disturbing the health of corals. The flow rate is defined as the amount or volume of water moved per unit of time and is usually provided in units such as gallons per hour or liters per hour. However there are no simple rules on how to adequately quantify the amount and type of water motion needed for aquarium success. Reasons for this include the lack of a detailed data and real understanding of the needed water movement or type of movement necessary for specific animals. In general, the amount of water motion for corals has been linked to the location of specimens relative to the reef zone (such as fore reef, reef flats, lagoon, etc). However in reality the water motion in the ocean is very chaotic both in short (seconds, minutes) and long (hours, days and longer) time scales. In an aquarium the amount of achievable flow at any point is further complicated and impacted by both aesthetic (non-living) and living (such as coral) structures, placement of pumps, and tank walls; all of which add friction, change flow direction and constrain or limit water movement. Also any structure in the path of water flow can induce change in flow directions, secondary flows, momentum losses, unsteadiness and turbulence.The aquarium industry characterizes the pumps using the flow rate - amount of water moved per unit of time (eg. Gallons/hr). However, the more accurate definition of volumetric flow rate is " the volume of fluid which passes through a given surface area per unit time" This definition indicates that there is a velocity component to the flow. For a fixed surface area, the volumetric flow rate can be increased or decreased by changing the flow velocity. Also, a fixed flow rate can be achieved by increasing the velocity and reducing the surface area or by decreasing the velocity and increasing the surface area.Given an area A, and a fluid flowing through it with uniform velocity V with an angle away from the perpendicular direction to A, the flow rate is: Q = (V)(A) cos θ (1) In the special case where the velocity is perpendicular to A, Q = (V)(A) (2) In general, the flow velocity at any location in the ocean (or in the aquarium) can be in any direction and can be defined by a vector or (3) Since the direction and magnitude of the velocity may change in time, the water velocity can also be defined by (4) where is the mean velocity component of the fluid and V' is the unsteady or time-varying component . The magnitude and direction of the unsteady component, V'(t) is a function of time. The unsteady component can also be sub-classified as deterministic (such as periodic or coherent variations in water movement due to waves or wakes from the rotating propeller blades) or non-deterministic (random motion or turbulence). Turbulence is initiated by shear or gradients in flowing water and is characterized by chaotic mixing of the water through large scale eddies which spawn ever smaller scale eddies. In the aquarium, water movement is typically achieved using powerheads or pump driven return pipes and closed loop circuits. The outlet portion of each of these devices results in the generation of a submerged jet similar to what is shown in Figure 1 for a simple submerged turbulent jet. Submerged jets are jets of water that flow into a reservoir (tank) of water. Contrary to common aquarium myth, in most cases, except possibly the smallest powerheads, the jet is turbulent and not laminar. Also, as will be shown in this paper, the exit flows from propeller driven pumps are much more complicated than a simple jet shown below. Figure 1. Schematic of simple turbulent jet [1] Introduction The use of propeller bladed pumps/powerheads for water movement in the aquarium industry has expanded significantly in the past few years with the advent of DIY, retrofit kits, and specific commercial lines. The first propeller pump available to reef aquarist consumers was created by Jimmy Chen in 2002 and sold as a retrofit kit to be installed on a Little Giant submersible pump [2]. While providing high flow rates with minimal power consumption, this product did not feature the benefit of long term research and development and was plagued by failures. Tunze unvieled the first widely available commercialized propeller pumps at Interzoo in May 2002 branded as the "Tunze Stream." The synchronous models of Stream were available at retail in July 2002 and the controllable models followed in November. They also offered brushless DC models which were capable of speed control through their own proprietary controller. In 2005 EcoTech Marine introduced a through-the-glass magnetically coupled aquarium pump, using a brushless DC, controllable motor. More recently, Hydor introduced their Koralia line of propeller pumps and made available controllable versions as well. The Hydor line of controllable powerheads is distinctly different from the Tunze and EcoTech Marine products because it utilizes low voltage AC current to drive the pumps and the controllers use frequency modulation to change the speed. The major difference of these two approaches is that brushless DC pumps are typically more expensive but their controllers are relatively inexpensive, whereas low-voltage AC pumps are more economical however their controller is expensive to produce. Generally, brushless DC pumps are capable of more precise rpm changes to enable flow augmentations such as pulsing for waves generation. The objective of the current experiment was to investigate a more accurate method to determine the volumetric flow rates for widely available models of propeller pumps. The advantage of propeller pumps is that they are capable of moving large volumes of water at very low pressures with minimal power consumption. Some DIY methods of measuring the flow rate of small pumps include timed bag filling experiments, pumping from one reservoir to another and placing the powerheads in a constrained systems (inlet or exit piped) with a flow meter. These types of tests however, can impart unrealistic hydrodynamic loads on the propeller pumps by altering the inlet and/or exit flows in ways that are not typically seen in our aquarium set ups. Adding piping and other constraints such as bags on the exit jet may impart back-pressure that can affect the pump's performance. These DIY methods add additional blockage (similar to covering the exit jet or inlet grating) which negatively reflects the true flowrate of the pump. In addition, the pump exit jet flow tends to expand radially as it exits the nozzle as shown in the Figure 1. Any intrusive method (such as a bag, added piping, increased pressure head between reservoirs) adds momentum and friction losses not accounted by most measurement methodologies. Therefore more sophisticated methods must be employed to obtain accurate flow readings from propeller driven pumps. An experimental method was developed incorporating acoustic Doppler velocimetry (ADV) technology, which has been used to measure open channel flow. The advantage of this methodology is that it is nearly non-intrusive and does not apply backpressure to the pump. It also measures the flow velocities directly in contrast to diffusion/dissolving methods which only infer flow rates [3]. The pumps included in this study are listed in Table 1 along with their manufacturer's advertised flowrate. Due to the expense of some of these products and constraints on the budget, every product on the market could not be included in this evaluation. The study was restricted to the following list of pumps shown in Table 1. Table 1. Pumps included in flow experiment Pump Advertised Output Flow (Gallons/hr) Aqueon 24002400Coralife CP 29002900Ecotech Marine MP-101575Ecotech Marine MP-403200Ecotech Marine MP-607500Hydor Koralia 51650Hydor Koralia 62200Hydor Koralia 72700Hydor Koralia 83250Maxijet 1200295Tunze 61053434Tunze 62055811Tunze 63057925The majority of the pumps included in this test cater to the high-end saltwater aquarium market. A less expensive traditional impeller driven Maxijet 1200 powerhead was included in this test as a comparison to propeller pumps. Theory Because these propeller based aquarium pumps operate between two fluid reservoirs that are at the same pressure, one cannot simply displace water from one reservoir to another without adversely affecting the accuracy of the measured volume flow rate. For this reason, a velocity measurement of flow is needed to determine the true volume flow rate through the pump. A single velocity measurement is not sufficient for propeller pumps since the flow velocity varies across the large diameter cross section of the exit nozzle. To accurately measure the velocity of the flow across the entire output profile, several sample measurements were taken at locations ranging from the very outside of the flow jet to the center of the flow jet. For the purpose of this experiment, the flow was divided into n distinct regions, illustrated in Figure 2. Figure 2. Division of flow based on radial position After measuring the flow velocity in these regions, the subsequent volume flow rate of the region can be found using VFRi = Vi*Ai (5) where, VFRi is the volume of water flowing per unit time through the incremental area Ai at velocity Vi . This calculation can be repeated over the velocity profile to yield the total volume flow rate of the system. This idea can be expressed as VFRs = Σ Vi * Ai. (6) The area of each region can be calculated using Ai = Ï€ * (ri2-r(i-1)2). (7) This type of calculation is known as a Reimann Sum, and is used to approximate real-world integration. The accuracy of this method depends greatly on the number of iterations completed. Experimental Apparatus For this experiment, a test setup needed to be developed that would accurately measure the velocity of water flow over a series of points across the flow profile. To accomplish this task, a Sontek 10-MHz Acoustic Doppler Velocimeter was selected for its ability to measure open-channel flow in a volume of water as small as 0.25 cc. The ADV selected also had the capability of measuring 3-Dimensional flow. Table 2 is taken from Sontek's literature for the 10 MHz ADV used. The ADV that was used to collect the velocity measurements was positioned using an extruded aluminum scaffolding system shown in Figure 3. The system was designed to be adjustable in the three dimensions shown, labeled X, Y, and Z. The vectors shown correspond to the ADV measurements taken for the X, Y, and Z directions. To accurately measure the position of the ADV over the course of each trial, the scaffolding structure in Figure 3 was fitted with Wixey Model WR510 digital positioning gauges on both the Z and the Y axes. The specifications for the gauges used are shown in Table 3. Table 2. Sontek Adv Specifications Sontek 10 MHz ADV Sampling Rate 0.1 to 25 HzSampling Volume0.25 ccDistance to Sampling Volume10 cmResolution0.01 cm/sProgrammed Velocity Range3, 10, 30, 100, 250 cm/sAccuracy1% of measured velocity, 0.25 cm/sMaximum Depth60 mTemperature Sensor0.1°CResolution - Heading,Pitch, Roll0.1°Accuracy - Heading±2°Accuracy - Pitch, Roll±1°Figure 3. Scaffolding support structure for ADV positioning Table 3. Specifications for Wixley Model WR 510 Wixey Model WR 510 Resolution:Decimal = .005 in.Fraction = 1/32 in.Metric = 0.1 mmAccuracy:Decimal = .0025 in.Fraction = 1/500 in.Metric = .05 mmFigure 4 shows the setup of the positioning and integration of one of the gauges used. This test setup allowed for accurate recording of the position of the ADV to within 0.05 mm, as listed in the specifications. Because positioning in the X direction was less critical, a tape measure was used to position the ADV at approximately one diameter downstream from the face of the pump, +/- 1/32nd of an inch. Figure 4. Integration of digital positioning gauges into scaffolding structure Figure 5 shows the final ADV positioning for testing of the Tunze 6305. As shown in the figure, the ADV is positioned at the centerline of the pump face and one diameter downstream from the face. Figure 5 also shows the particulate matter that was suspended in the tank for the duration of testing. These particulates were the seeding material provided by Sontek in order to increase the signal-to-noise ratio returned by the velocimeter. Figure 5. Initial positioning of the ADV during testing Besides the velocity components and standard deviation of the axial velocity, the power consumption and the rotational speed of each pump were recorded. The power consumption was monitored through a wattmeter which is shown in Figure 6. The rotational speed of each pump was determined using the strobe tachometer shown in Figure 7. Figure 8 shows the tachometer in use while testing the Coralife CP 2900. Figure 6. Watt meter used in testing Figure 7. Strobe tachometer used in testing Figure 8: Coralife pump as seen under strobe lighting Test Procedure Before testing could begin on any of the pumps, an appropriate measurement time duration needed to be established to ensure that enough samples were taken to accurately represent the measured flow velocity and minimize measurement bias. To determine this duration, a value of the turbulence intensity was determined for several trials of differing time durations. The turbulence intensity FT is calculated using Equation 11, where is the standard deviation of the axial velocity and Vavg is the mean of the sample velocity. FT = σ / Vavg (8) The turbulence intensity is a value representing the degree of unsteadiness or fluctuations in the measured flow field. An ideal steady flow with absolutely no fluctuations would have a turbulence intensity value of zero. When measuring unsteady flows, care must be taken to ensure that the fluctuations are accounted for and do not lead to temporal biasing of the mean velocity measurements. Theoretically, the mean velocity and turbulence intensity values will approach constant values as the sample time is increased to infinity. The reason for this is that as sample time is increased, any temporal bias in the measurement will be reduced. During the test, two trials were averaged at various time intervals to produce the data shown in Table 4. The data was then plotted in Figure 9 to locate the "shoulder" of the curve, or the point that would produce reliable and accurate velocity data. Table 4. Turbulence factors calculated for various time durations. Turbulence Intensity Data Time (sec) Sigma (ft/sec) V (ft/sec) FT 00.302.50.120200.212.20.095300.142.40.058400.122.30.052450.112.50.044500.112.50.044600.112.40.046Figure 9. Turbulence Intensity plotted for various time durations As shown in Figure 9, the point at which the turbulence intensity curve leveled off was found to be about 45 seconds. This duration was determined adequate to represent the velocity data for the pumps. For the extent of the test, velocity samples were taken using this time duration for sampling at each location. Figure 10. Illustration of velocity measurement locations With the time of each sample established, flow testing on the pumps could begin. The output nozzle diameter was measured for each pump and recorded for later use. Flow testing was broken down into two sets of trials for each pump: a horizontal set and a vertical set. The two data sets allowed the flow to be broken into four quadrants, providing a more accurate measure of the entire velocity profile. The data points taken are shown in Figure 10. To begin taking data, the ADV was positioned such that the sampling volume of the measurement corresponded to the center of the pump output and was located one diameter downstream of the nozzle, as illustrated in Figure 5. The ADV was first positioned well outside the range of the flow, which was defined as a stagnant, or near zero, X velocity. The velocimeter was then moved in the positive Y direction across the velocity profile in 5mm increments until a non-stagnant X velocity was observed. Velocity measurements were then recorded for successive 5mm increments for the entirety of the profile until a stagnant velocity was reached at the corresponding location on the opposite side of the flow jet. This process was repeated moving the ADV vertically to achieve the measurements shown in Figure 10. The raw data taken during the testing needed to be corrected before it could be used to calculate the volume flow rate. To begin, the velocity measurements taken from the velocimeter were in component form. The three velocity components (along the X, Y and Z axis) needed to be combined through vector addition in order to produce the final velocity measurement for the given location. This process is described through Equation 12, where Vtotal is the combined velocity, and Vx,y,z are the individual component velocities. This is an important step as the rotating propeller blades in many of the tested designs swirl the flow in a screw like fashion. The exit jet also expands as it leaves the pump. A simple one component velocity measurement may underestimate the actual water velocity. Vtotal = (Vx2 + Vy2 + Vz2)1/2 (12) The next modification to the data was made to "center" the measured points. This process was done to ensure that the velocity measurements taken matched up correctly to their radial location used in the flow calculation. Centering the data involved a set of criteria described below: If the data contained an obvious flow deficit ("void") which represented the center of the propeller, the data was centered such that the void was assigned a radial position of 0 mm. If the measured data did not contain an obvious flow deficit the data was centered symmetrically over a radial position of 0 mm. To measure the power consumed by each pump, the power source was run through the wattmeter shown in Figure 6. There was often a "settling" period observed where the pump initially drew slightly higher wattages, so the power value was recorded after taking the velocity measurements. One exception made to this procedure was the measurements made on the MaxiJet 1200. This pump had an output diameter of less than ½", making measurement difficult at one diameter downstream. To compensate for the small output radius and ensure enough data points were taken, the ADV was positioned 1" downstream from the face of the pump. Due to the lack of a visual propeller on the MaxiJet, the pump speed was not measured. Results Using the data collected, the flow profiles of the pumps was computed in the Z (vertical) and Y(horizontal) directions. The majority of the pumps tested produced nearly symmetric velocity profiles. Figures 11, 12 and 13 show the Ecotech Marine MP-60, the Tunze 6305, and the Hydor Koralia 8, respectively, which are examples of pumps that exhibited somewhat symmetrical flow fields. These figures show the results of both the horizontal and the vertical data sets for each pump. In these examples, it is seen that the MP-60 and Tunze 6305 produced a broad and comparably gentle flow, where the Koralia 8 produced a more concentrated jet with a higher peak velocity. The flow profiles for all the pumps is presented in Appendix 2. The reader should note the differences in complexity of the flow generated by the propeller generated pumps compared to that of a traditional impeller driven powerhead like the Maxijet 1200 (see Figure Appendix 2.7). The complexity of their exit flow field that makes simple single point measurement methods unreliable in determining rated flow rates. Figure 11. Velocity Profile of Ecotech Marine VorTech MP-60 Figure 12. Velocity Profile of Tunze 6305 Figure 13. Velocity Profile of Hydor Koralia 8 Uncertainity and Error While the Sontek specifications state a measured accuracy of +/- 1% of the reading, in actual situations this error will be higher. There are several sources of error and uncertainity that contribute to the flow calculations, some of which are listed below Approximations used for integration depend on the granularity of data and number of points sampled Unsteady nature of the flow field, due to blade wake passing, asymmetric or blocked inflow, inlet and exit grill interactions, ADV vibrations, etc. Based on these flow profiles, the volumetric flow rate was calculated. The results are presented in Table 5. The column on the far right labeled "% Change from Manufacturer's Claim" is a comparison between the calculated experimental flow and the manufacturer's stated maximum output flow. This calculation is expressed by (13) Table 5 represents the data such that a positive change indicates an increase in the observed flow from the manufacturer's claim and vice versa. The data is shown graphically in figure 15. Table 5. Test results for the various pumps at maximum power Pump Pump Speed (RPM) Power Use (Watts) Calculated Flow (Gal/hr) % Change of Mean from Manufacturer's Rate Aqueon 2400360014.2274414.30%Coralife CP 2900360018.82437.2-16.00%Hydor Koralia 53600222597.5957.43%Hydor Koralia 6360021.82205.60.30%Hydor Koralia 73600122659.1-1.50%Hydor Koralia 83600183188.3-1.90%MaxiJet 1200Unknown20.7405.737.50%Tunze 61053250242358.2-31.30%Tunze 62053160453234-44.30%Tunze 63053060483597.3-54.60%VorTech MP-10327019.82460.356.20%VorTech MP-402440293781.218.20%VorTech MP-602100538509.813.5%Figure 14. Comparison of Advertised Output Flowrates with Measured Output Flowrates Another metric that could be use to evaluate the pumps is the Flow Efficiency, measured as the ratio of measured flowrate to actual power consumed. Table 6 and Figure 15 summarizes the flow efficiencies in units of GPH/watt. As shown, the pumps are broken into three different categories: AC (non-controllable), ACC (controllable), and DC (controllable). While the AC models offer better flow efficiencies, they do not offer the flexibility of output modification or advanced programming. The highest efficiency for the ACC pumps was the Hydor Koralia 7 and for the DC pumps was the Ecotech Marine Vortech MP-60. Table 6. Summary of flow Efficiencies Pump Flow/Power (GPH/watt) Power Type (AC/DC) Aqueon 2400193.2ACCoralife CP 2900129.6ACHydor Koralia 5118.8ACCHydor Koralia 6101.2ACCHydor Koralia 7221.6ACCHydor Koralia 8177.1ACCMaxiJet 120019.6ACTunze 610598.3DCTunze 620571.9DCTunze 630574.9DCVortech MP-10124.3DCVortech MP-40130.4DCVortech MP-60160.6DCFigure 15. Flow Efficiency of the Pumps Tested Conclusions A standard method for evaluating flow rates of pumps using ADV was developed, and applied to measurement of flow of several popular aquarium propeller pumps. Data obtained during this study shows that the generated flow field is more complex than a simple submerged jet and therefore single point measurements may not accurately represent the flow rate. After the completion of this experiment, it is clear that there is a difference between many of the measured results and their manufacturer's advertised performance. While most aquarium manufacturers are within a reasonable range of their claimed flows, there were some notable exceptions. As shown, measured values of volume flow rate for the Aqueon, MaxiJet, and EcoTech Marine models were generally higher than advertised flow outputs. The Hydor 6, 7, and 8 were measured to within 2% of the manufacture specifications. The Hydor 5 and Vortech MP-10 both presented an anomaly in that they produced 55-60% more flow than claimed. In fact, the Koralia 5 that was tested produced significantly more flow than the Koralia 6, and almost matched the output of the Koralia 7. The reason for this difference in claimed and experimental flow measurements is unknown. On the other hand, for the Tunze units' measured flow rates were consistently under the advertised flow rates on the models tested. In the case of the Tunze 6305, the measured flow was less than half that of the manufacturer's claimed flow. Further investigation may be needed to determine how this manufacturer originally developed the advertised flow rates of each of its models (see Addendum). Another conclusion that can be drawn from this experiment is that there is a wide range of flow efficiencies shown. The flow efficiency, or unit of flow observed per unit of power consumed, varies greatly from manufacturer-to-manufacturer and model-to-model. The flow efficiency values are presented in Table 6. Hobbyists have seen significant advancements in the range of aquarium circulation pumps available over the past decade. While all manufacturers provide a flow rate for the pumps, it is not clear what methods have been used to arrive at the numbers. Further, different manufacturers may use different methods. We have presented a standard method that we hope can be adopted by the manufacturers thus enabling a more accurate and verifiable approach. Addendum On completion of the study, the paper was sent to Tunze and Hydor prior to this publication. Based on these results, Tunze conducted its own independent tests on the Tunze pumps and have confirmed our results. On further discussion with Tunze we do not feel the errors were deliberate attempts to mislead, but rather their misguided faith in theoretical calculations that often do not translate well into real world application and use. In light of these finding Tunze is working to remedy the situation. For any resolution on how Tunze will address this please refer to Tunze's website for more information. Acknowledgment 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. References Blevins, R. D., Applied Fluid Dynamics Handbook, Van Nostrand Reinhold Co., New York, 1984. Harker, Richard. "Product Review: Propeller Pumps In The Aquarium." Advanced Aquarist. Pomacanthus Publications, LLC. Web., <a href=../../2002/6/review">http://www.advancedaquarist.com/2002/6/review. Riddle, Dana. "Feature Article: Measuring Water Movement in Your Reef Aquarium for Less Than $100." Advanced Aquarist. Pomacanthus Publications, LLC. Web., http://www.advanceda quarist.com/2011/1/aafeature. Taylor, John R. "Chapter 3." An Introduction to Error Analysis: the Study of Uncertainties in Physical Measurements. Sausalito, CA: University Science, 1997. Print. Appendix 1: Example of Sample Data (Data Sample from Ecotech Marine Vortech MP-40) Editor's note: The original article contained an embedded table that was to be displayed in-line with the article. Due to width constraints, we have instead converted this data into an image and are providing the data as an Excel spreadsheet and Adobe PDF. [*]Excel File[*]Adobe PDF File Appendix 2: Plots of Velocity Profiles Appendix 2.1. Velocity profiles of the Aqueon 2400 Appendix 2.2. Velocity profiles of the Coralife CP 2900 Appendix 2.3. Velocity profiles of the Hydor Koralia 5 Appendix 2.4. Velocity profiles of the Hydor Koralia 6 Appendix 2.5. Velocity profiles of the Hydor Koralia 7 Appendix 2.6. Velocity profiles of the Hydor Koralia 8 Appendix 2.7. Velocity profiles of the MaxiJet 1200 Appendix 2.8. Velocity profiles of the Tunze 6105 Appendix 2.9. Velocity profiles of the Tunze 6205 Appendix 2.10. Velocity profiles of the Tunze 6305 Appendix 2.11. Velocity profiles of the Ecotech Marine Vortech MP-10 Appendix 2.12. Velocity profiles of the Ecotech Marine Vortech MP-40 Appendix 2.13. Velocity profiles of the Ecotech Marine Vortech MP-60 View the full article

Welcome to SRC ! Care to share more about your Aqua Illumination LED ? Is your corals adapting well to the light ? How is the shimming effect of this light ?

Yes, you can use those filter media and reuse for your marine tank . Happy reefing