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Discussion Starter · #1 ·
ok this may be one of the easiest DIY projects i have ever done. i have made 3 different sizes. 1/4, 3/8, and 1/2. they seem to be working but i would like someone else to give them a try. i am running the 1/4 and 3/8 right now on a mag 12. i know this can pump out enough and they do seem to be working. the 1/2 is on my quiet one. this also seems to be working to some extent. the problem is i can not tell whether it is actually pumping more volume or just pushed the velocity way up.

they are only composed of 3 pieces. i was able to find all of them at Lowe's. no glue is required! only drilling some inlet holes for the water.

Parts list 1/4":
1/4"X1/2" nylon barb to MIP adaptor A-193B made by Watts
1/2"X1/2" slip to FPT coupler PVC
1/2"X3/4" MPT to slip adaptor PVC

Parts list 3/8":
3/8"X1/2" nylon barb to MIP adaptor A-300 made by Watts
1/2"X1/2" slip to FPT coupler PVC
1/2"X3/4" MPT to slip adaptor PVC

Parts list 1/2":
1/2"X1/2" nylon barb to MIP adaptor A-387 made by Watts
3/4"X3/4" slip to FPT coupler PVC
3/4"X3/4" MPT to slip adaptor PVC

i think the 3/8" works the best. i think the barb fits in the nozzle better.

i am curious on the 1/4". if it will work on smaller pumps. it should require less back pressure to be effective. this may be usefull for some smaller pumps that can not push a 10' pump height.

construction is simple, and the same for all 3. the coupler is the nozzle extension. this acts as a longer travel area so that the pumped water will pull more water from behind the barb. the non barb adaptor is drilled in order to allow the water be pulled in by the barb. i drilled 8 holes each 3/8" in diameter. this is the cool part. the barb adaptor fits perfectly inside the drilled adaptor. the barb sticks into the MPT part of the adaptor. i have tried cutting of a section of the barb to see if it helps and it seems to. right now i have it so the barb ends where the MPT part of the adaptor starts. that is it! just use whatever adaptors you need to get the 1/2"MPT part of the eductor into your system. i am pretty sure the total cost of each of these is under $2!

i would like some feedback on your experiences here. i am still trying to decide where the crossover point is between just increasing velocity of the water and actually drawing more flow. i know i am getting more total flow in the tank. all my stonies have opened up more!

the construction pics are of the 1/2" version.

G~
 

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Discussion Starter · #3 ·
1/4" one without the nozzle extension. i forgot to buy an another coupler.:rolleyes: i removed 3 of the barbs on this one. this is how i decided it works best when the barb ends right where it enters the adaptor.

G~
 

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Discussion Starter · #4 ·
the 3/8" one. this one is complete and seems to be working the best out of all of them. i have not tried the 1/2" though on the mag 12. the mag 12 can push more head pressure than the quiet one.

G~
 

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Discussion Starter · #5 ·
the 1/2" one. the reason this one is on the Quiet One is this CL has a valve on it so i can adjust the two outlets. right now i have the valve almost completely closed. when the valve is completely closed i can pust some water through this eductor. this is the one i am having the hardest time decided if it is the eductor actually working or just an increase in water velocity. no coments please about the number of adaptors i had to use to get it connected to my CLS.:)

thanks for looking, please give feedback if you try it. i think it is well work the $2. considering a store bought eductor is $30! i can definately tell the fish are having to swim more in the tank!

i could not let galleon and Spanky have all of the eductor fun. :D

G~
 

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A goof
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That looks very slick, from what I have read to make eductors work properly you need a high head pressure pump, much moro like an Iwaki pressure pump.

You can start making them and sell them on the side ;)

Jon
 

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Discussion Starter · #7 ·
you are correct. here is where i was looking at the pressures required. my mag 12 comes close to the needed pressure. this is why i am trying the 1/4" hoping it would need less pressure to function properly. it seems to.

G~
 

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Discussion Starter · #8 ·
did some playing around last night with the sizes and pumps, and it seems that they are behaving just the opposite of what i was thinking. i put the 1/4" on the Quiet One and it just laughed at me. the flow went way down. so it looks like the smaller the eductor the greater the pressure needed to function. now that i think about it, it makes sense. i put the 1/2" on the mag 12 and look out. all kinds of crazy flow. this is also without full pressure behind it. i hope to try it will full pressure behind it sometime. i also cut 2 barbs off of the 1/2" to see if that helped, it did.

from what i can see it looks like the 1/2" is behaving like an eductor on the mag 12. it may not be doing 5X the flow but i do think it is doing 2x at least. it is drawing water in through the drilled holes. if i raise the eductor close to the surface of the water a small wirlpool will form above the holes.

G~
 

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Discussion Starter · #9 ·
just an update. i have the 1/2" versions on all four of my CLS outlets. WOWWSERS. there is a tremendous amount of flow in the tank. the fish have to swim now to stay still!

i think this size is the best. it seems to work fine on both the Quiet One and the Mag 12. i do think it is pushing more water than before even without the high pressure. i think it would be a lot higher if there was a pressure pump behind it though. i think i have doubled the flow out of the nozzles. i do not think i quadrupled it like what should happen with a high pressure pump.

i am now starting to get sand movements. pretty cool. put it this way. i have a 3 inch conch. over 4 feet away from the eductor that was on, the conch was rolling on the SB due to the current! i angled it up more since then so the conch would have an easier time doing its job.:)

G~
 

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kewl Geoff. I'll have to pick up some extra fittings next time I go to Lowes. So your opinion is that the 1/2" one works the best? I guess I'll have to buy a couple of the threaded ends for my loc-line also. Do you think a Mag 9.5 will run the 1/2" one ok? 180 Large, an eductor is designed to increase the flow in a tank by way of drawing tank water in through the eductor powered by the return water to increase the total volume of water moved. An eductor goes on the end of a return or on the outlet of a closed loop. They can be anenome and fish blenders though so they have gotten a little bit of a bad rap. Some skimmers are retrofitted with eductors to increase the efficiency.
 

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thanks do they do any damage to the pump at all? Is there some way to put a screen of some type over the end or will that defeat the purpose? Maybe one of those cone screen that go bulkhead fittings and powerheads. Just a thought.
 

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The pump will never know it is there. The only problem with a screen or sponge is that it will get really dirty and increase nitrates. If it does get clogged though it won't hurt the pump since it is still pumping the same amount of water. An example of an eductor is one of the waterbed draining devices you hook up to the bathroom sink. The faucet water draws the bed (tank) water through it using little faucet water to remove a large amount of bed water. Does that help?
 

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Discussion Starter · #17 ·
Joel-yea, i think the 1/2" work the best when a pump is not powerfull enough to really run an eductor properly. you could easily run one on the 9.5, you could try two. remember to make sure your PVC is well glued. the back pressure for the pump will increase. do not want any snug fittings to come loose on ya.

since these are not running at high pressures they are not as dangerous to critters in the tank. they are not drawing ridiculous amounts of water through the eductor holes, so most critters will be fine. i have a sea hare that has crawled onto the eductor without harm. now he is 8 inches long. something smaller than the eductor inlet holes may not fare as well though.

eductors are only increasing the amount of flow that is leaving the nozzle. not what the pump is rated at.

example: totally off the cuff calcs here- my mag 12 is rated at 1200 gph. the flow out of a 1/2 hole on this pump is say 900 due to back pressure. the eductor may be doubleing this so its final output is near 1800 gph not 2400 gph. just a little clearification.

G~
 

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I understand the principle but am obviously unable to accurately convey my thoughts in a post. I also have a Little Giant 4-mdqx-sc rated @~1300gph. Would the 1/2" ones be big enough for that? Right now I'm running it through 2 3/4" loc-lines wide open and I have quite a bit of movement but it is a 28" deep tank and detritus still gathers in some areas on the bottom. (not a lot of movement at the bottom).
 

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Discussion Starter · #19 ·
according to my previous findings on what is needed to run a3/8" eductor "properly" 10psi is needed, or 23 feet of head pressure. you little giant gets up to 17' of head pressure before it stops pumping. this is pretty close, althought the flow is way down. since you are closer than my mag 12 i would definately try the 1/2" and the 3/8". i would not try the 1/4". i think it would be very close to the switchover point. with the 3/8" you may get enough pressure to really suck some water throught the back side of the eductor! the 1/2 will definately get you some more though. for less than a couple of bucks, go for it. i think you will be surprised. i was.

G~
 

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gonna try to make it by lowes today. I'll let you know how it goes
 
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