Set-By-Step Eductors to replace powerheads

[Evolution]

For those of you that don't know what an educator is, it's basically a device installed on the output of your return pump in the main tank that increases your flow. Not pump flow but water movement. The high pressure stream of water creates a vacuum leaving a low pressure area behind the stream. This draws in water through the outside holes. So basically you take a small direct stream of water and can mix it with surrounding tank water to create a much larger higher volume of flow out of your output. This can increase the water movement in your tank by 5X.

I have read a few other DIY threads on these so I thought I'd give it a go in my tank.

The Rio 2500 I got with my sump was way too much flow for just one small output nozzle. So I'm using a PRO4 pump that is moving about 300 gph. Pretty pathetic for my system. So I really want to up the turnover to my sump to 600+ GPH by using the RIO2500. So I'm splitting the output into 2 returns then running eductors on them to maxamize the water movement.

I have a powersweep (170 GPH) powerhead and a Hagen (200 GPH) powerhead for movement. Also my return. After seeing the flow that other people here have in their tanks, I'm now aware that I am very low on movement. I also have 5 or 6 areas on the sand that are collecting grey debris from lack of current. So it's time to turn things up a notch.

This was very simple and cheap to make and man does it move some serious water.

Here are the parts used:

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor001.jpg

And the rough finished eductors before polishing everything.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor002.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor003.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor004.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor005.jpg

I ran a 200 gph powerhead to a 5/8" ID vinyl hose to a ten gallon tank. With the pump running, the 5/8" tubing sprayed pretty decent and made some swirling but the stream was very small, thin and lost momentum quickly.
I hooked the eductor up to the end of the tubing and turned it on. The eductor thrust backwards as it sucked water from behind it and the entire tank was spiraling and there was sand everywhere. With the enductor I had at least 4 times the flow in the tank and the water leaving the nozzle was in a 2" diameter stream that made a wall of water movement. It is incredible.

Here it is in the water:

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor008.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductor009.jpg

When I get the other one done and installed, I'll post some video of the difference in flow in my main tank.

Since I have to build another one, I can take pictures and post some descriptions if anyone is interested in building one.

[Evolution]

Well I took pictures just in case someone would be interested. I think these things are awesome. It's amazing the difference they make in flow.

The first step is to drill the 1/2" holes in the area directly behind the output nozzle. I drilled them straight first on a press. The plastic is soft so be sure to drill at a low speed so you don't melt it and also don't go too fast or the bit will grab the fitting and spin it.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding001.jpg


Next you want to slant the holes towards the water direction. This isn't necessary but it adds some efficiency. The smoother the transition for the water, the more you'll move. I did this by freehand on the press. I don't recommend anyone without experience using a drill press to try this. It's easy for the fitting to catch and possible break your fingers, or tear them off. I'd advice using a dremel to slant the holes.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding002.jpg

The series of smaller intake holes help pull a bit of extra water into the large nozzle. They are also slanted.

Next I notch the back of the fitting to accept the 90 deg elbow.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding003.jpg

You want the lip on the elbow to sit inside the fitting which just happens to be perfectly centered.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding004.jpg

Next cut the elbow behind the last barb:

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding005.jpg

And trial fit it. You want the water nozzle just at the front of the main intakes so that you have a large low pressure area to suck in as much water as possible.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding006.jpg

Now to create a stronger high pressure area, I heated and compressed the tip of the elbow so it was just a hair smaller. This is not necessary. Most return pumps, mine included, will have a lot of pressure coming out of a 5/8" elbow (which is 1/2" inside). I just did it for the heck of it.

Then sand (dremel) the outside so that the tip is paper thin. This taper will also help water being sucked in, to flow over the nozzle easily as it passes by.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding007.jpg

Next cut a 3/4" piece of 5/8" ID thick wall Vinyl tubing and notch it to accept the vertical elbow nipple.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding008.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding009.jpg

[Evolution]

Then cut a 3/4" piece of 3/4" thin wall Vinyl tubing and cut it open. Spread it over top of the other tubing and you should have a nice tight fit inside the large fitting.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding010.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding011.jpg

Now spread some Medium CA glue onto the elbow and slip the 5/8" tubing over. Then spread a thin layer on the tubing and snap your other tubing on. Now spread a bit of glue inside the large fitting and slide the whole thing inside. Quickly check the nozzle tip inside the fitting to be sure it is centered best you can and pointing true to the fitting.

I added a few drops of accelerator into the back to set the glue instantly.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding012.jpg

Now fill the back with a 5 minute epoxy and heat to accelerate.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding013.jpg

Now sand the back smooth and flat.

And you're done. Now you've turned 2 X 5/8" outputs into 2 X 2" outputs. And increased your water movement by loads.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding014.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding015.jpg

I added some gutterguard on to the outside of mine with some CA. This is just to keep small fish from taking a ride through the eductor or a larger fish from getting itself stuck in the suction against the fitting. I know my puffer's would have their heads stuck in there in no time.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorbuilding016.jpg

They are by no means beautiful but they cost me $0 and will get 2 power heads, 2 plug ins and 2 heat sources out of my display. Plus increase the flow for the corals. I could have spent more time making everything perfect but what the heck. I just wanted to whip these up to try them and now that I have, I will always use them.

I also like that I managed to make them out of Grey fittings. White just looks horrible in a display and I wanted to use black or Grey so they aren't as noticeable. Once covered in coraline, it won't matter anyway I guess. :)

[Richy]

Cannot wait for the video...Nice work!

Rick..

[Adam NS.]

I have to ask how is this different from a venturi? it looks like its the exact same principle. or is it just the difference in name?

[Evolution]

Venturi is similiar, if not the same. The device itself is called an eductor.

I got the new pump and eductors installed. I'll post a bunch of pics and videos later. It makes a huge difference in the volume of water moved around my tank. Lots of my dirty sand areas are self cleaning now. A stronger pump would make these even better same with reducing the size of the output nozzle and manifold. But I just wanted something quick and free to improve my movement and this did the trick. Plus I removed 2 powerheads (heat sources as well as power consumption) which is nice to free up the space, and increased my water movement, as well as doubling the turnaround through my sump, since the Rio2500 with 2 outputs is cycling alot more water than my old Pro4 pump and 1 output.

[Evolution]

I took a few pictures. Here is setting up the new return system.

This is the old setup:
http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall001.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall002.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall003.jpg

And the new parts:

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall004.jpg

I ran 3/4" line from the pump to the Y so I needed a way to adapt the 3/4" to the 5/8". So I inserted a piece of thin wall 5/8" ID tubing and slipped the fitting in. It is very tight.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall005.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall006.jpg

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Eductorinstall007.jpg

Well that's all the picture I had time for. But here are a couple of the videos. Short and crappy quality but you get the idea.

This is one of the before shots. This corner had the best movement but still, very minimal.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Videos/th_Eductorinstall009.jpg (http://s138.photobucket.com/albums/q253/gfisher2002/Fish/Videos/?action=view&current=Eductorinstall009.flv)

After installing the new return and eductors, my Green Star Polyps get a hurricane of flow over them in the center of the tank.

http://i138.photobucket.com/albums/q253/gfisher2002/Fish/Videos/th_Eductorinstall014.jpg (http://s138.photobucket.com/albums/q253/gfisher2002/Fish/Videos/?action=view&current=Eductorinstall014.flv)

I have more pics and video but I don't have time to post it. I'll put it up later.