Great, cheap, and functional DIY eductors!
- Thread starter liveforphysics
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liveforphysics
New member
ctreefer- Perhaps the most clever thing about making your own eductor is making the orifice size to suit your pump. If you have a low pressure pump, you can make a larger orifice to suit the pressure ability of your pump. The downside is of course a lower flow multiplier ratio. A large orifice design may only result in a 2:1 flow boosting ratio, but reguardless, you doubled your flow for a couple of dollars without increaseing heat or power consumption.
Also, if you wish to increase the head pressure ability on a pump, you can use epoxy putty to reduce the diameter of the inlet area, and bring the surface as close to the impeller as possible. Starting with a pump that features realitively tight fitting impeller housings would be a bonus as well. While you are working with the houseing, radius the outlet passage, and you may compensate for the flow lost from increaseing the head abilitys.
Just another 20mins with some frag mounting putty and a dremel sort of mod, but you may be suprized at what you can do for the pump.
Best Wishes
Also, if you wish to increase the head pressure ability on a pump, you can use epoxy putty to reduce the diameter of the inlet area, and bring the surface as close to the impeller as possible. Starting with a pump that features realitively tight fitting impeller housings would be a bonus as well. While you are working with the houseing, radius the outlet passage, and you may compensate for the flow lost from increaseing the head abilitys.
Just another 20mins with some frag mounting putty and a dremel sort of mod, but you may be suprized at what you can do for the pump.
Best Wishes
liveforphysics
New member
I've had a generous offer from rogergolf66 who says he has both the time and ability to test the performance of the different nozzle designs. I will be sending them out to him today.
I looking forwards to seeing his results shared with the board. This way we will get some solid ideas on what shapes and orifice sizes perform best.
I looking forwards to seeing his results shared with the board. This way we will get some solid ideas on what shapes and orifice sizes perform best.
Luke,
I have always wanted to try this with a low pressure pump like a Dart. Paul (OM) and I have talked about this before. Even if you only get 1.5:1 its still an improvement, if you are not cutting down the original flow by restricting it that is.
liveforphysics
New member
Thank you for the kind word Johnathan!
H20ENG- The return pump on my reef is a dart. I use 4 0.375" orifice eductors on the outputs. It moves loads more water with them than without them. Not just a sorta noticeable thing, but a need to re-aim them from sandstorm and water over the edge of the tank sort of flow increase.
Dart and eductors is a definate winner. Also, the pump draws about 15watts less power with the eductors installed.
I've not tried an oceans motions in the mix with a dart and eductors. After going to a VFD drive wave pulse system for my closed loop, I gave my OM's away.
Best Wishes
H20ENG- The return pump on my reef is a dart. I use 4 0.375" orifice eductors on the outputs. It moves loads more water with them than without them. Not just a sorta noticeable thing, but a need to re-aim them from sandstorm and water over the edge of the tank sort of flow increase.
Dart and eductors is a definate winner. Also, the pump draws about 15watts less power with the eductors installed.
I've not tried an oceans motions in the mix with a dart and eductors. After going to a VFD drive wave pulse system for my closed loop, I gave my OM's away.
Best Wishes
liveforphysics: very clever and simple, wish I would have read this before buying my eductors. regarding your VFD drive wave pulse system for your closed loop, what is VFD and can you elaborate on what you are using?
also, I have eductors on the 4 return lines of my OM 4 way running on a Sequence Barracuda and the backpressure is too much for the version 2 drum to rotate. Paul at OM recommends trying a version 3 drum which I am planning to do.
also, I have eductors on the 4 return lines of my OM 4 way running on a Sequence Barracuda and the backpressure is too much for the version 2 drum to rotate. Paul at OM recommends trying a version 3 drum which I am planning to do.
BenjieC
New member
Here you go: http://www.reefcentral.com/forums/showthread.php?s=&threadid=1183020&perpage=&pagenumber=1
Enjoy, I know I did.
Zucker26
New member
I have a 29gal display with a 10gal sump, but I'm running a 1500gph pressure-rated return pump (I know, I know, but it was only $20 and I was still in school). Since I'm circulating so much water through a 10gal sump, I have some very creative bubble traps. I have been told many times that my tank is WAY too small to need educators, and I agree. However, this post made the think...
The current coming from two returns connected to a SCWD is perfect right now without throttling the pump back, but I would LOVE to be able to cut the flow across my sump in half. I think I could make even smaller versions of your educators, then throttle back my pump by about a third, which would allow me to get rid of some of the bubble traps and maybe add a fuge.
Do you think adding educators and throttling back my return pump would be a viable way to decrease the flow across my sump while still maintaining the current in my display?
The current coming from two returns connected to a SCWD is perfect right now without throttling the pump back, but I would LOVE to be able to cut the flow across my sump in half. I think I could make even smaller versions of your educators, then throttle back my pump by about a third, which would allow me to get rid of some of the bubble traps and maybe add a fuge.
Do you think adding educators and throttling back my return pump would be a viable way to decrease the flow across my sump while still maintaining the current in my display?
Zucker26
New member
As a chemical engineer, this is probably supposed to make complete sense to me, but I do have one question of clarification.
If I'm currently running 3/4" return lines, then any outlet smaller than that will increase flowRATE (velocity). If I want to maintain my current flow velocity but increase the volume of water being moved, then I could make an educator with a 3/4" outlet which would maintain the velocity of flow but increase the volume of water being pushed.
Is that correct, or is my GameDay buzz still going strong?
If I'm currently running 3/4" return lines, then any outlet smaller than that will increase flowRATE (velocity). If I want to maintain my current flow velocity but increase the volume of water being moved, then I could make an educator with a 3/4" outlet which would maintain the velocity of flow but increase the volume of water being pushed.
Is that correct, or is my GameDay buzz still going strong?
Zucker26: an eductor works by a different principle than decreasing the size of a pipe outlet. eductors create a negative pressure area caused by the flow being pushed through them. This negative pressure is rapidly "filled" with surround water into the eductor's central stream, creating a large water mass movement. they are used primarily in large vats of paint, oil, etc. for mixing purposes. eductors will cause significant resistance or back pressure which is why one needs a pressure rated pump to drive them properly.
Now, getting back to your application, if you put an eductor on the end of your sump return your flow where the eductor is sitting will INCREASE, due to the large water mass movement it will cause. However, the flow behind the sump's pump, which is the flow across your sump will DECREASE, due to the resistance or back pressure the eductor is applying to the pump. Or you can open up the pump's outlet valve a little to compensate for the resistance and maintain the same flow through your sump.
So, yes you could make an educator with a 3/4" outlet which would maintain the velocity of flow but increase the volume of water being pushed.
Now, getting back to your application, if you put an eductor on the end of your sump return your flow where the eductor is sitting will INCREASE, due to the large water mass movement it will cause. However, the flow behind the sump's pump, which is the flow across your sump will DECREASE, due to the resistance or back pressure the eductor is applying to the pump. Or you can open up the pump's outlet valve a little to compensate for the resistance and maintain the same flow through your sump.
So, yes you could make an educator with a 3/4" outlet which would maintain the velocity of flow but increase the volume of water being pushed.
Last edited:
Pbrown3701
New member
I made one of these today for my 74 bowfront. I already had a purchased eductor running on an Iwaki 70RLT. I added this DIY version to the opposite side of the tank facing the purchased one. It seems to work every bit as good as the OEM. The flow from the DIY actually seems a little bit stronger than the original.
Thanks for the design live!
Thanks for the design live!
liveforphysics
New member
Pbrown3701- It was my pleasure to give back to the comunity, and it makes me feel great to hear that it is working as well as your professional eductor. You are very welcome.
Coralite- You are likely the man best suited towards the tricky task of at least qualitatively evaluating the different designs of eductor. If I were to create a variety of designs and send them to you, would you be willing to test and share your results?
BTW- I really respect the work you've done with the science of the interaction between waterflow and corals. Keep up the great work!
Best Wishes,
-Luke
Coralite- You are likely the man best suited towards the tricky task of at least qualitatively evaluating the different designs of eductor. If I were to create a variety of designs and send them to you, would you be willing to test and share your results?
BTW- I really respect the work you've done with the science of the interaction between waterflow and corals. Keep up the great work!
Best Wishes,
-Luke
coralite
registered member
Hi Luke,
Thank you for all the kind words. I am developing a pretty thorough water flow study which will first evaluate not flow rates but "water movement" by various water pumps and their placement. Although I will be focusing on various water pumps to begin with, i do intend to evaluate water flow accessories to see how they affect overall water movement and you can bet eductors and penductors will be evaluated. However, I probably wont get a chance to do the flow accessories for awhile. However, if you wanted to cook up a few modified eductors I would be glad to give them a review and see if we can tweak the designs for different applications.
On another note, howzabout a video of the dramatic flow alternation in your tank? Put some flake food in there so we can see the flow and post it online for us to see. I have a youtube channel to use if you want to post it to a video sharing site.
Thank you for all the kind words. I am developing a pretty thorough water flow study which will first evaluate not flow rates but "water movement" by various water pumps and their placement. Although I will be focusing on various water pumps to begin with, i do intend to evaluate water flow accessories to see how they affect overall water movement and you can bet eductors and penductors will be evaluated. However, I probably wont get a chance to do the flow accessories for awhile. However, if you wanted to cook up a few modified eductors I would be glad to give them a review and see if we can tweak the designs for different applications.
On another note, howzabout a video of the dramatic flow alternation in your tank? Put some flake food in there so we can see the flow and post it online for us to see. I have a youtube channel to use if you want to post it to a video sharing site.
scottflanagan
New member
I was looking at the eductor/penductor website and they suggest using one or two at most.
I was thinking of doing 4 on a pump that is rated for 580 gph.
I am using a panworld 50px and don't want to put too much head pressure on it. I also want to direct the flow in multiple locations.
No mater how much the flow is reduced(2.5 gpm[gallons per minute] in my case w/4) it should still create that low pressure area thus pulling more water out of the tank for circulation. Correct?
Penductor's web site has a chart:
It seems they claim no mater how many GPM you force through it the gain is always at a factor of five.
Now i have only taken one physics and 2 calcs but i would think the gain would be more complex than liner equation.:reading:
If it is corect than the adition of 4 eductors would alow my 50px to circulate 3000 gph around my little tank!!:uzi:
Could this be so?
Also would it matter if they were close to the top? I would not want to pull air into my tank.
I was thinking of doing 4 on a pump that is rated for 580 gph.
I am using a panworld 50px and don't want to put too much head pressure on it. I also want to direct the flow in multiple locations.
No mater how much the flow is reduced(2.5 gpm[gallons per minute] in my case w/4) it should still create that low pressure area thus pulling more water out of the tank for circulation. Correct?
Penductor's web site has a chart:
It seems they claim no mater how many GPM you force through it the gain is always at a factor of five.
Now i have only taken one physics and 2 calcs but i would think the gain would be more complex than liner equation.:reading:
If it is corect than the adition of 4 eductors would alow my 50px to circulate 3000 gph around my little tank!!:uzi:
Could this be so?
Also would it matter if they were close to the top? I would not want to pull air into my tank.
