# Barr Internal Venturi CO2 Reactor



## hoppycalif (Apr 7, 2005)

I just finished making a Barr Venturi reactor, per the sketch on Tom's website,
Barr Report - Venturi Design. I used a Catalina 400 powerhead, because it is cheap and about the right size. The tube is a Viewtainer Viewtainer Plastic Storage Container 2" x 6". The elbow at the outlet of the powerhead is from the lawn sprinkler area of the hardware store, an elbow going from 1/2" tube riser to 1/2" male threads, with most of the female part cut off so it fits into the viewtainer. I used a piece of a powerhead outlet deflector to make a prop to better stabilize the weight of the powerhead on top of the viewtainer, which has a soft plastic end cap. The suction cups are a hose retaining suction cup for a cannister filter hose, with the hose clips cut off, and everything is glued together with aquarium silicone sealant. I plan to use a small sponge on the inlet to avoid it plugging up with plant debris and snails. Total cost is around $30, including shipping for the viewtainer.


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## Jason Baliban (Feb 21, 2005)

That is quite a contraption you got there. I have no doubt it will work, but do you think it will create a large enough positive difference to make you overlook that huge thing sitting in your tank? 

jB


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## ianiwane (May 6, 2005)

Also you do not need to use the larger viewtainer. The smaller one will work just fine. I do not think the sponge is need either, as long as this thing is turned off at night it should not clog.


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## hoppycalif (Apr 7, 2005)

The viewtainer I used is about the smallest one they make. This looks huge in the photos, but in a 45 gallon tank, 18" front to back and about 20 inches deep, this will be easily hidden in a forest of either vals or crypts. I will definitely turn off the CO2 at night, but not necessarily the powerhead. The added circulation at night could be beneficial. Right now, my CO2 mist system doesn't get enough CO2 dissolved into the water, so my goal is to obtain most of the benefit of the mist system, plus get 20-30 ppm of CO2 in the water. If needed, I will add a mist system later with the second powerhead in the water, which will start out as just a sponge filter unit.


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## hoppycalif (Apr 7, 2005)

I finally managed to switch tanks from the 29 gallon to my 45 gallon today, and the Barr Internal Venturi reactor is up and running. So far it is still purging the air bubble that got trapped in the viewtainer. I have it with a CO2 bubble rate of about 2 per second, but I will need to do some pH/KH, etc. measuring to see where I should have it. It really works nicely, except I need to raise it a bit so it doesn't drill a hole in the substrate. No sponge filter - the idea of shutting it down at night so the debris can fall off appealed to me.


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## hoppycalif (Apr 7, 2005)

The Barr reactor wasn't working just like I expected, but today I did a big water change, and left the CO2 on for about 5 minutes without the powerhead being on. When I restarted it I got just what it is advertised to do. It has a big swirl of big CO2 bubbles at the top of the tube, the venturi line has a constant flow of CO2 bubbles back to the powerhead inlet, it is producing CO2 mist out the bottom, the CO2 bubble mass is stable, and it burps excess bubbles occasionally. If my wife hadn't borrowed my camera I would post a pic of the action! I now have about 3 bubbles per second thru the bubble counter, which is 1 bubble per second in the reactor tube (larger bubbles). I'll see if the fish show any distress before I try to change anything.


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## hoppycalif (Apr 7, 2005)

I have moved my CO2 reactor to the front of the tank for now, so I can monitor what it is doing better. It photographs better there too. Here it is in action:










It has the water at 30 ppm of CO2 now, about an hour after it started operating.


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## epicfish (Sep 11, 2006)

Hm, nice! I wish I could make one too, but it'd be too big for my 10 gallon. Gonna stick with the nano glass diffusers. =)

Great setup and picture.


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## hoppycalif (Apr 7, 2005)

I have been trying to clean out all of the algae I can find in my tank, an almost impossible job. One problem is that algae is growing inside the viewtainer part of my venturi reactor, and it's construction is so flimsy that I can't do an effective job cleaning it out. So, I made another one, with some changes. First, I discovered the secret to finding viewtainers in the stores. Orchard Supply Hardware keeps them in the tools section, where it is very easy to overlook them, but after searching the entire store I found them. Only $2 for a 2" diameter by 6" long version.

So, here is what I ended up with:


















This one is made from my Maxijet 600 powerhead. I have the outlet going into the side of the top of the viewtainer instead of down thru the top to an elbow. (I got this idea from someone else who mentioned it in this forum) It is a bit off center on purpose. The purpose is so I can use the existing suction cups on the powerhead to mount it making it much more securely mounted. Next, I have the CO2 inlet coming in thru the side of the viewtainer instead of thru a long tube down from the top. This makes it easier to brush out the inside. Finally, I have a coarse sponge on the inlet to the powerhead to keep baby shrimp, etc out. Tomorrow I will see how well it works.

edit: Here is the monster in the tank:


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## surpera1 (Feb 18, 2009)

so - is this the most efficient co2 diffuser design ? i have a diy 2 two liter co2 generator - so i cant really control the amount of co2 being fed into it - but i have an airstone on a timer at night - would this put too much co2 into my tank ? could i put the powerhead on a timer and have it off at night ? it would then act as a less efficient bell right ? have you noticed a difference with this design ?


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