Why do we assume a large return pump is needed?
- Thread starter Herbert T. Kornfeld
- Start date
pjf
Premium Member
Additional Lessons
Additional Lessons
This forum has taught me a lot about efficiently providing water flow in our aquariums. It would be remiss if we did not also explore the water flow requirements for our corals.
Per Jake Adams, water flow is more important than light for corals:
Part 1: http://www.advancedaquarist.com/2006/6/aafeature2
Part 2: http://www.advancedaquarist.com/2006/8/aafeature/view
Apparently, water flow must go hand-in-hand with light intensity:
Part 3: http://www.advancedaquarist.com/2006/9/aafeature2/view
Part 4: http://www.advancedaquarist.com/2006/11/aafeature
We need to extrapolate this information to optimize water flow for corals in our aquariums. Are there any additional lessons that can be gleamed from this series of articles?
For example, to save energy, can we turn off our main tank's flow devices at night and only leave the return pump on?
Additional Lessons
This forum has taught me a lot about efficiently providing water flow in our aquariums. It would be remiss if we did not also explore the water flow requirements for our corals.
Per Jake Adams, water flow is more important than light for corals:
Part 1: http://www.advancedaquarist.com/2006/6/aafeature2
Part 2: http://www.advancedaquarist.com/2006/8/aafeature/view
Apparently, water flow must go hand-in-hand with light intensity:
Part 3: http://www.advancedaquarist.com/2006/9/aafeature2/view
Part 4: http://www.advancedaquarist.com/2006/11/aafeature
We need to extrapolate this information to optimize water flow for corals in our aquariums. Are there any additional lessons that can be gleamed from this series of articles?
For example, to save energy, can we turn off our main tank's flow devices at night and only leave the return pump on?
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hahnmeister
In Memoriam
As far as the corals are concerned, you might be able to from the standpoint that they dont need the flow to go with their light, but the resperation of the rest of the tank does depend on the flow to keep the gas exchange and nitrogen cycles going... otherwise you might end up with depleted oxygen, and pH dips that are out of control as not only gasses build up, but badcteria release acids.
pjf
Premium Member
Return Pump Flow Enough at Night?
Return Pump Flow Enough at Night?
Let’s assume that we have an RDP algal refugium. The return pump and the main tank’s flow devices have two distinct roles. The return pump transports oxygenated water from the refugium to the main tank and causes CO2 and nitrates to drain to the refugium via the overflow. This helps to prevent pH dips. The flow devices simply “stir the water†to help diffuse gases and DOC’s evenly throughout the main tank and ensure that there are no “dead spots†with low flow.
At night, there is no coral photosynthesis and metabolic activity is down with the exception of that generated by nocturnal fauna. The role of the main tank's flow devices diminishes. At night, isn’t the flow produced by the return pump alone enough?
Return Pump Flow Enough at Night?
Let’s assume that we have an RDP algal refugium. The return pump and the main tank’s flow devices have two distinct roles. The return pump transports oxygenated water from the refugium to the main tank and causes CO2 and nitrates to drain to the refugium via the overflow. This helps to prevent pH dips. The flow devices simply “stir the water†to help diffuse gases and DOC’s evenly throughout the main tank and ensure that there are no “dead spots†with low flow.
At night, there is no coral photosynthesis and metabolic activity is down with the exception of that generated by nocturnal fauna. The role of the main tank's flow devices diminishes. At night, isn’t the flow produced by the return pump alone enough?
bergzy
New member
i was thinking about getting a red dragon as a return pump...but as i did the math...
an ampmaster 3200 (with max flow of 3400 gph) uses 138 watts which works out to 0.043 to 0.040 watt per gallon per hour with a pump cost of $257.99 at marine depot.
the red dragon uses 0.04 watts per gallon as well with a pump cost of $599 at captive oceans.
i must say that red dragons are slick though!!!
hahnmeister
In Memoriam
Red Dragons are also not high-head pumps... they are the opposite extreme, and although they can pump alot of water at minimal head, they lose their flow very quickly against head-pressure. Not to mention, they arent exactly what this thread is about.
pjf, Considering the idea of this thread is to have the smallest pump possible on your reef for return plumbing, I dont know that 200-300gph on a 180g at night would be a good idea. Dont get me wrong, many products and reefs are set up for a 'night-time' mode, but thats still a considerable amount of flow. Also, EVERY photosynthetic organism does continue to operate at night, so to suggest that they have no metabolic activity couldnt be farther from the truth... the night cycle for corals involves giving off CO2 (the cycle runs in reverse), and acid in the process. This is why flow is still important. Reduction in flow is okay, but to cut back to a bare minumum might end up killing some corals.
Also remember that night time is when corals come out to feed... SPS, LPS, etc. And without flow... this isnt going to happen very easy.
pjf, Considering the idea of this thread is to have the smallest pump possible on your reef for return plumbing, I dont know that 200-300gph on a 180g at night would be a good idea. Dont get me wrong, many products and reefs are set up for a 'night-time' mode, but thats still a considerable amount of flow. Also, EVERY photosynthetic organism does continue to operate at night, so to suggest that they have no metabolic activity couldnt be farther from the truth... the night cycle for corals involves giving off CO2 (the cycle runs in reverse), and acid in the process. This is why flow is still important. Reduction in flow is okay, but to cut back to a bare minumum might end up killing some corals.
Also remember that night time is when corals come out to feed... SPS, LPS, etc. And without flow... this isnt going to happen very easy.
pjf
Premium Member
Time for Sea Change
Time for Sea Change
Thanks, Hahnmeister.
In my 75g aquarium with 29g sump/refuge, I am considering replacing my ~800gph Iwaki MD-30RXT with a slower and quieter pump. The flow rate is strong enough to bring the water level to the top of the Mega Flow drain slots and cover the bottom of the glass brace. Two questions:
• What external return pumps do you recommend? A couple of years ago, Iwaki and Eheim were tops but I’m sure that things have changed.
• What flow devices do you recommend in the main tank? I’m considering two Vortech pumps mounted on the left and right ends of the back glass to provide an alternating current but I’ve no idea what flow controllers are available.
Time for Sea Change
Thanks, Hahnmeister.
In my 75g aquarium with 29g sump/refuge, I am considering replacing my ~800gph Iwaki MD-30RXT with a slower and quieter pump. The flow rate is strong enough to bring the water level to the top of the Mega Flow drain slots and cover the bottom of the glass brace. Two questions:
• What external return pumps do you recommend? A couple of years ago, Iwaki and Eheim were tops but I’m sure that things have changed.
• What flow devices do you recommend in the main tank? I’m considering two Vortech pumps mounted on the left and right ends of the back glass to provide an alternating current but I’ve no idea what flow controllers are available.
hahnmeister
In Memoriam
Eheim is still a top choice for an external/internal pump. The 1250 would suit you nicely, giving you about 2.5x turnover per hour. Another good choice comes from the Pan World guys, the 40PX, but that would give you slightly more flow... about 350-400gph. My choice would be the eheim.
As for the flow... The Vortech pumps are nice, as long as you dont mind the hockey-puck stuck to the outside ends of your tank. As of yet, there are no controllers though... it was supposed to be out sometime right about now though. There have been some problems, and they do give off a slight hum, but Icecap is a reputable company that Im sure will take care of their customers.
Other options:
Tunze Streams. A pair of 6000s (1800gph) would be a good match for a 75g, and a controller is readily available. The 6000s can have their transformer swapped out for about $70 and then they are 6100s (3000gph). The disadvantage is that you have a larger pump in the tank to hide, of course, but its more adjustable as well. With some good planning, a Tunze stream can be hidden in an artificial rock. Check out how Iwan's new tank hides the Tunzes... they are so well hidden that nobody has even commented on how well he has hidden them because you cant even see them from the front. They are hidden in little ceramic/aragacrete shelves/walls in the corners of the tank, even up in the corners. The only way I noticed them was because I saw them listed on his equipment list and looked real hard. Also, there are the new Tunze Nano-streams coming out, and the variable speed 6055 which is due this month ramps up to 1500gph.. plenty for a 75g, and those little 2.5" black balls are easier to hide than maxi-jets. The only disadvantage is that they top out at 1500gph... plenty for a 75g, but not expandable should you decide to upgrade to a larger tank in the future... sorta. I suppose the 6055s would still work on a larger system as a secondary flow provider... perhaps down behind the rocks to kick up sediment or provide flow in some hard to reach areas.
Another option is a closed loop and pump. Im not as much of a fan as I used to be of these. I think its just a PITA to drill glass... run pipe outside the tank, deal with leaks and such, and the largest PITA is that the outputs are fixed, and after time... its usually not where you want them. As the tank grows, you can move a powerhead or add one... a closed loop is forever in the same place. And IMO, they arent all that much easier to hide than a powerhead. They are still a bulkhead on the back wall sticking out at you with loc-line to direct the flow. My closed loops required cleaning out every 6 months (a complete gutting and cleaning), took up alot of space behind the tank, and IMO... not worth it. When you look at where the flow is coming from and going, often times the best flow is not from behind the rocks either. Its pretty hard to give a nice wide arc of flow from a nozzle situated right behind the rock where you are trying to make the flow. With most closed loops, the front glass ends up getting the best flow because half the nozzles end up facing the front of the tank in some manner.
Well... except for those systems that are 100% in the tank/HOB. Hang on back loops are adjustable, and rather easy to do. I think they are often overlooked because people are drawn to the more elaborate/expensive drilled tanks and bulkheads, but there is no reason why you cant just hang your pipes on the back of a tank. If you have a canopy, they actually are less obvious than a drilled tank style loop, because all of the piping can run over the back of the tank, and the only part of the nozzle(s) or intake showing in the tank can be kept to just the top few inches of the tank. A manifold that goes around the parimeter of the tank with outlets facing down into the tank is easy to make, easily modified and adjustable as the tank grows, and if you have a canopy... invisible. Also, something I have done similar to the closed loop is to run some piping inside fake rock, or aragacrete. On my nano, I have a aragacrete wall across the entire back, and inside that rock, and only visible from the top for pump removal/cleaning is a complete pump and closed loop setup. The pipes all run through the rock, and the pump is hidden inside as well. Its completely invisible and many people come over and cant tell where the flow is even coming from because the aragacrete completely covers the back wall, piping, and overflow. In my new 100-150g project, I will be using a sub-sand loop, fed by a powerhead, to kick up the sand under the rocks. So internal closed loops... Im all for em. The only main drawback of a closed loop is that you still have to use a centrifugal pump, which isnt the best flow/watt when you compare to a SEIO or Tunze type pump. Soon, SEIO will have a Polario unit that might change all that.
But like I said above for closed loops, pay attention to flow always. If you want good flow across your tank from left to right, you put the outlets at each end of the tank facing each other. If you want a specific rock to get the flow, you dont go putting the powerhead in the rock, you put it across the tank aiming at it! So many times I see people with flow coming from the parts of the tank that should be getting the flow... defeating the purpose. The best places for closed loop outlets are not the back wall behind the rocks, or even through the bottom (except those few that have nozzles at the front edge blowing up at the corals on the rocks at the top)>>> the best places for closed loop outlets are the top of the tank (a manifold in the canopy), and the ends... blowing water to the corals at the bottom and across the tank.
The other option is MJ streams, or SEIOs, or some other prop style pump that is attached to an oscillating device... a DIY 'swirler-stein', a WavySea, a SeaSwirl, Osci-Motion, etc. These are perhaps the best application of a prop driven powerhead, because rather than having to use a controller to vary the output of the pump, the pump stays on all of the time... only moving its output back and forth from just 90degrees to a full 180 if you wish with some units. This provides more flow than one pump that has a fixed direction and flow that varies from 30%-100%, hitting every corner of the tank with flow as its output can cover just so much more. The disadvantage: good luck covering that moving powerhead up in the tank. Then again, stream modded MJs are pretty small, and if you have a deeper tank (like 2'+), they are much less noticable in the back corners.
As for the flow... The Vortech pumps are nice, as long as you dont mind the hockey-puck stuck to the outside ends of your tank. As of yet, there are no controllers though... it was supposed to be out sometime right about now though. There have been some problems, and they do give off a slight hum, but Icecap is a reputable company that Im sure will take care of their customers.
Other options:
Tunze Streams. A pair of 6000s (1800gph) would be a good match for a 75g, and a controller is readily available. The 6000s can have their transformer swapped out for about $70 and then they are 6100s (3000gph). The disadvantage is that you have a larger pump in the tank to hide, of course, but its more adjustable as well. With some good planning, a Tunze stream can be hidden in an artificial rock. Check out how Iwan's new tank hides the Tunzes... they are so well hidden that nobody has even commented on how well he has hidden them because you cant even see them from the front. They are hidden in little ceramic/aragacrete shelves/walls in the corners of the tank, even up in the corners. The only way I noticed them was because I saw them listed on his equipment list and looked real hard. Also, there are the new Tunze Nano-streams coming out, and the variable speed 6055 which is due this month ramps up to 1500gph.. plenty for a 75g, and those little 2.5" black balls are easier to hide than maxi-jets. The only disadvantage is that they top out at 1500gph... plenty for a 75g, but not expandable should you decide to upgrade to a larger tank in the future... sorta. I suppose the 6055s would still work on a larger system as a secondary flow provider... perhaps down behind the rocks to kick up sediment or provide flow in some hard to reach areas.
Another option is a closed loop and pump. Im not as much of a fan as I used to be of these. I think its just a PITA to drill glass... run pipe outside the tank, deal with leaks and such, and the largest PITA is that the outputs are fixed, and after time... its usually not where you want them. As the tank grows, you can move a powerhead or add one... a closed loop is forever in the same place. And IMO, they arent all that much easier to hide than a powerhead. They are still a bulkhead on the back wall sticking out at you with loc-line to direct the flow. My closed loops required cleaning out every 6 months (a complete gutting and cleaning), took up alot of space behind the tank, and IMO... not worth it. When you look at where the flow is coming from and going, often times the best flow is not from behind the rocks either. Its pretty hard to give a nice wide arc of flow from a nozzle situated right behind the rock where you are trying to make the flow. With most closed loops, the front glass ends up getting the best flow because half the nozzles end up facing the front of the tank in some manner.
Well... except for those systems that are 100% in the tank/HOB. Hang on back loops are adjustable, and rather easy to do. I think they are often overlooked because people are drawn to the more elaborate/expensive drilled tanks and bulkheads, but there is no reason why you cant just hang your pipes on the back of a tank. If you have a canopy, they actually are less obvious than a drilled tank style loop, because all of the piping can run over the back of the tank, and the only part of the nozzle(s) or intake showing in the tank can be kept to just the top few inches of the tank. A manifold that goes around the parimeter of the tank with outlets facing down into the tank is easy to make, easily modified and adjustable as the tank grows, and if you have a canopy... invisible. Also, something I have done similar to the closed loop is to run some piping inside fake rock, or aragacrete. On my nano, I have a aragacrete wall across the entire back, and inside that rock, and only visible from the top for pump removal/cleaning is a complete pump and closed loop setup. The pipes all run through the rock, and the pump is hidden inside as well. Its completely invisible and many people come over and cant tell where the flow is even coming from because the aragacrete completely covers the back wall, piping, and overflow. In my new 100-150g project, I will be using a sub-sand loop, fed by a powerhead, to kick up the sand under the rocks. So internal closed loops... Im all for em. The only main drawback of a closed loop is that you still have to use a centrifugal pump, which isnt the best flow/watt when you compare to a SEIO or Tunze type pump. Soon, SEIO will have a Polario unit that might change all that.
But like I said above for closed loops, pay attention to flow always. If you want good flow across your tank from left to right, you put the outlets at each end of the tank facing each other. If you want a specific rock to get the flow, you dont go putting the powerhead in the rock, you put it across the tank aiming at it! So many times I see people with flow coming from the parts of the tank that should be getting the flow... defeating the purpose. The best places for closed loop outlets are not the back wall behind the rocks, or even through the bottom (except those few that have nozzles at the front edge blowing up at the corals on the rocks at the top)>>> the best places for closed loop outlets are the top of the tank (a manifold in the canopy), and the ends... blowing water to the corals at the bottom and across the tank.
The other option is MJ streams, or SEIOs, or some other prop style pump that is attached to an oscillating device... a DIY 'swirler-stein', a WavySea, a SeaSwirl, Osci-Motion, etc. These are perhaps the best application of a prop driven powerhead, because rather than having to use a controller to vary the output of the pump, the pump stays on all of the time... only moving its output back and forth from just 90degrees to a full 180 if you wish with some units. This provides more flow than one pump that has a fixed direction and flow that varies from 30%-100%, hitting every corner of the tank with flow as its output can cover just so much more. The disadvantage: good luck covering that moving powerhead up in the tank. Then again, stream modded MJs are pretty small, and if you have a deeper tank (like 2'+), they are much less noticable in the back corners.
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pjf
Premium Member
Great Writeup!
Great Writeup!
Hahnmeister,
While the Eheim pumps are excellent, they do have barb fittings. Are there no pumps with threaded fittings that are as quiet and as well made?
Compared to the “10 x Volume†turnover guideline from a couple of years ago, the flow rates that you are citing for flow devices are very high (1500gph-3000gph). What is the recommended turnover rate today?
I plan to install Vortechs on the back glass. They will be near the side corners and will be pointing forward. This should hide the electrical cords and external assemblies in the back. I plan to switch the flow direction every few minutes. While this is not the best orientation for left-right flow, I believe that the initial forward current will round the front corners and turn to flow left or right. The controller and the noise are still issues, so I will watch for the Vortechs to mature in 2007.
Thanks for your comprehensive survey of flow devices! You have saved all of us a lot of time that would otherwise be spent researching the market.
Great Writeup!
Hahnmeister,
While the Eheim pumps are excellent, they do have barb fittings. Are there no pumps with threaded fittings that are as quiet and as well made?
Compared to the “10 x Volume†turnover guideline from a couple of years ago, the flow rates that you are citing for flow devices are very high (1500gph-3000gph). What is the recommended turnover rate today?
I plan to install Vortechs on the back glass. They will be near the side corners and will be pointing forward. This should hide the electrical cords and external assemblies in the back. I plan to switch the flow direction every few minutes. While this is not the best orientation for left-right flow, I believe that the initial forward current will round the front corners and turn to flow left or right. The controller and the noise are still issues, so I will watch for the Vortechs to mature in 2007.
Thanks for your comprehensive survey of flow devices! You have saved all of us a lot of time that would otherwise be spent researching the market.
pjf
Premium Member
I understand that the Eheim's threads are European. Where can I find a bulkhead or NPT adapter for it?<a href=showthread.php?s=&postid=8761395#post8761395 target=_blank>Originally posted</a> by jnarowe
pjf: The Eheim 1250(60?) that I have came with both. I don't use barb fittings and it works great on my reactor.
hahnmeister
In Memoriam
Well, they are 'universal' threads. They are technically metric, but they made them so you can thread US fitting in there as well. The US fittings fit a little looser, but some teflon tape takes care of this. The 1260/1262 series has a 3/4" inlet and 3/4" outlet. The 1250 has a 1/2" inlet and 3/8" outlet. The 3/8" makes it pretty much restricted to just using the hose though, as there isnt alot of 3/8" PVC around (There is, but its not worth it). FWIW, you could use a 3/8"-1/2" adapter and just use 1/2" CPVC/PVC though. Its such a small pump though... IMO, who cares if the return line to the tank is in flexible hose. I just use 1/2" ID - 5/8" OD common flexible hose on mine.
markandkristen
Active member
pretty cool thread
I'm torn if an eheim 1262 would be enough flow looking for good quiet application and good energy rating for my 200 gallon system. I have already added some additional flow with a pair of Hydro #4's. I have been listening to the hummmmmm of this iwaki for years. I would like a better solution.
a. eheim 1262
b. panworld 30 or 40x
c. dart snapper
d. titianium 4
the panworlds are another interesting pump...
30hdx 1110 gph @ 90 watts $139
40hdx 1270 gph @ 130 watts $165
a. eheim 1262
b. panworld 30 or 40x
c. dart snapper
d. titianium 4
the panworlds are another interesting pump...
30hdx 1110 gph @ 90 watts $139
40hdx 1270 gph @ 130 watts $165
hahnmeister
In Memoriam
For a sump return, you might want to include the height change from the sump to the system... some tanks are a mere 3-4' of height change, some are basement sumps with 10' heights to overcome.
The Pan Worlds are great pumps for higher-pressure returns with lower wattages. They maintain pressure much better than say, the eheim 1262 or oceanrunner 3500. I wouldnt bother with the dart/snapper, they are flow pumps and unless used in minimal pressure applications (and large piping), they lose alot of their output.
The T4 is another great option. The tradeoff between a T4 and say, a Pan World is that the Pan is fan cooled, and so that exposure to the surrounding environment means it doesnt heat the tank as much, sure, but you can hear it more. The T4 is water cooled, almost like an eheim or oceanrunner, just not able to run submerged. They are super quiet because of this, but also add some heat to the water. If heat isnt a concern (with 200gallons, if you did, I would be looking at other problems then rather than the pumps), then the T4 is a great choice, but its still a bit large unless you intend to use it as a basement return (which it is excellent at).
The Pan Worlds are great pumps for higher-pressure returns with lower wattages. They maintain pressure much better than say, the eheim 1262 or oceanrunner 3500. I wouldnt bother with the dart/snapper, they are flow pumps and unless used in minimal pressure applications (and large piping), they lose alot of their output.
The T4 is another great option. The tradeoff between a T4 and say, a Pan World is that the Pan is fan cooled, and so that exposure to the surrounding environment means it doesnt heat the tank as much, sure, but you can hear it more. The T4 is water cooled, almost like an eheim or oceanrunner, just not able to run submerged. They are super quiet because of this, but also add some heat to the water. If heat isnt a concern (with 200gallons, if you did, I would be looking at other problems then rather than the pumps), then the T4 is a great choice, but its still a bit large unless you intend to use it as a basement return (which it is excellent at).
Running the chiller on the closed loop you are still adding heat from the closed loop pump just as you would by sizing the sump return pump to be within the chillers flow specs. I understand the low flow idea but sometimes there are tradeoffs and one has to make choices. my tank is not drilled to and hanging multiple pipes for closed loop flow was a less appealing option for me than using in tank prop pumps.
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