# Barr Internal Venturi CO2 Reactor



## Hoppy (Dec 24, 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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## PMD (Jan 28, 2006)

*Barr reactor*

Hoppy,

Looks great and very professional.

What size tank will you be using it on?

Regards,

PMD


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## plantbrain (Dec 15, 2003)

Home Depot, OSH sell the viewtainers: 1.99$.
Rigid airline tubing: 69 Cents
Rio 180 on line: 8.99$

Cost:11-12$


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## Martin (Jan 15, 2005)

let's see it in action.


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## Hoppy (Dec 24, 2005)

This will go into my 45 gallon tank, which has been sitting in the dining area for two months awaiting me getting all of the other stuff needed ready. The tank is a Jebo Odyssea with about 16-18 inches front to back, and about 20 inches tall.

Tom, my Home Depot doesn't have viewtainers, and if I ordered a Rio powerhead on line the shipping would have brought the price above $20. My LFS adds shipping costs to their prices, so the Rios there are more costly than the Catalina ones. I already had the CO2 tubing, and odds and ends of plastic, but had to buy 4 different elbows to get one that would work ok - those aren't that cheap at the hardware store. Plus, the aquarium sealant was $6 at the LFS. So, yes it did cost me about $30. But, I admit it could have been done cheaper.
I have been posting here about my 45 gallon tank for two months now, and it isn't set up yet, so I can't show it in action yet. That will come! I now have my continuous water change system pretty well installed, and am only waiting for a new filter sponge to be ready to start the switch over.


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## plantbrain (Dec 15, 2003)

Hi, 
Yea, I know the constraints you had there for cost.
But if you had emailed me, I have all the stuff here locally and some free Anubias coffeefolia :thumbsup: 

AquaticQuotient.com

There's a version working in the tank.


Regards, 
Tom Barr


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## Hoppy (Dec 24, 2005)

plantbrain said:


> Hi,
> Yea, I know the constraints you had there for cost.
> But if you had emailed me, I have all the stuff here locally and some free Anubias coffeefolia :thumbsup:
> 
> ...


But, I didn't know that! In a way it's just as well. My 29 gallon tank is almost totally filled with overgrown plants now, so I wouldn't have anyplace to put any other plants - not until I get the 45 gallon tank going, and not all of the plants I have will even fit in there. I see a RAOK coming! (Especially spiral vals.)


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## cbennett (Oct 20, 2005)

i can't seem to wrap my head around the purpose of the tubing that goes from the intake to the middle of the clear tube.


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## fshfanatic (Apr 20, 2006)

cbennett said:


> i can't seem to wrap my head around the purpose of the tubing that goes from the intake to the middle of the clear tube.


The powerhead pulls water from the tube causing a whirpool effect.


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## Hoppy (Dec 24, 2005)

If the bubble of CO2 builds up until it reaches where the tube is it sucks CO2 back to the inlet of the powerhead to recycle it as tiny bubbles, many of which will probably escape as CO2 mist. If the bubble gets even bigger, occupying another half inch of the big tube it burps out the burp hole. This allows DIY use with shutdown of the powerhead at night, while the CO2 keeps running, but just burps to the surface. So, DIYer will have a easy way to "shut off" the CO2 at night.


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## BSS (Sep 24, 2004)

Nice photos, Hoppy. Let us know how it works out.

Actually, it looks a lot like the first internal reactor I build for my 29g with DIY CO2. I did add an air stone to the bottom of my CO2 line to help break up the bubbles, and I certainly didn't have the feedback look and burp hole. Might have to break it out and modify it and give it a spin. Oh, and I used an old gravel vac for my 'tube' part.


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## Hoppy (Dec 24, 2005)

The viewtainer makes it look good. And, we all know that something that looks good works good. Right? I may just use mine as an art object for awhile.


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## Betowess (Dec 9, 2004)

Very cool Hoppy. Do you know what size tank (up to) it might be recommended for? Also, what is the GPH of a Catalina 400? I can't find it yet online. Is it around 120 GPH? Oh yeah, I just subscribed to the BarrReport. LOL


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## BSS (Sep 24, 2004)

Hoppy said:


> And, we all know that something that looks good works good. Right?


And, it does look simply mauvhelous, dahling!! (to be said in your best Zsa-zsa Gabor accent...now that should bring back some memories ).

Thinking about my original reactor from back when, I simply attached the gravel vac opening to the output of the powerhead with the water flowing straight down. Now, I'm thinking a real key is to have the powerhead output come out at a 90 degree angle from the tube so as to get that swirling action. Hmmm. Might be worth a trip to HD to find one of those colored Viewtaners. Oh, I do so hope that they have on that matches the trim of my tank :hihi: !


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## plantbrain (Dec 15, 2003)

They do come in a variety of colors BTW.
The 90 degree angle gets around the poorly designed commercial designed that ripped off my original idea. Some poorer designs require a sponge at the end. Those blast off and lose too much gas and are unsightly. The venturi loop always messed with others and few understood it so many never added it, another poor design mistake.

That's what happens when someone copies your stuff, but does not understands it. So I show folks the better designed and nice looking DIY model and folks can make it for 1/5th the cost:thumbsup: 

Now if you keep adding more CO2, too much etc, the excess gas will burp out the hole opposite the pump and venturi side, so you have 3 ways of expelling gas from this unit/design. 

1. Initially 100% dissolution
2. CO2 Mist
3. Burping slef regulation if you add too much

You never have to stop the flow gas(eg good for non solenoid user and DIY yeast folks) either. Simply turn off the powerhead to stop diffusion, the excess gas will burp out the top through the "burp" hole.

If you louse it up making it, the viewtainer is only 1.99$, so you can make another easily.

The venturi loop self regulates the CO2 level inside the reactor.
The efficacy is 100% until the gas builds up to this level, then the venturi suction from the powerhead's suction side starts pulling the gas in through the impeller and chops it up even further(2x , once in the venturi pull and then again through the impeller). The mist is gently expelled out the bottom in a downward flow and around the tank much like a diffuser disc except the mist is going down, not up and there's active flow out of the reactor.

This is also a self leveling device and bleches out any gas buld up in the reactor.

I think some copy cats thought the venturi was a bad since it appears to waste CO2, but that is not entirely true, the venturi is an advantage, not a detraction, you should have a fair amount of CO2 and be able to regulate it with a reactor, this one does that automatically for the most part if you use DIY yeast CO2.

A Rio 180 will run about a 40 gal tank, a 4x2 viewtainer is about all you need, longer and larger does not work as well as 2 such small units on either sides of the tank.

You'll also note ADA suggest multiple diffusers on larger tanks, rather than one big monster diffuser. Makes CO2 diffuser much more even this way rather than around a single point source. 4x2 reactors are easy to hide also.

Regards, 
Tom Barr


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## Betowess (Dec 9, 2004)

plantbrain said:


> That's what happens when someone copies your stuff, but does not understands it. So I show folks the better designed and nice looking DIY model and folks can make it for 1/5th the cost:thumbsup:
> 
> Now if you keep adding more CO2, too much etc, the excess gas will burp out the hole opposite the pump and venturi side, so you have 3 ways of expelling gas from this unit/design.
> 
> Tom Barr


This is true. The "mini vortex" reactor, which was my first reactor, had a bad habit of having too much gas build up inside and because it was to be mounted vertically, it had a tendency to develop an airlock within the rio, if one was really cranking the CO2 to reach 30ppm. I had to retire it and went with a traditional inline reactor which Rex helped me concept out. That 30 bucks is still sitting on the shelf of aquaria junk.


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## plantbrain (Dec 15, 2003)

Post like that warm my wittle heart:flick:

Regards, 
Tom Barr


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## Hoppy (Dec 24, 2005)

Betowess said:


> Very cool Hoppy. Do you know what size tank (up to) it might be recommended for? Also, what is the GPH of a Catalina 400? I can't find it yet online. Is it around 120 GPH? Oh yeah, I just subscribed to the BarrReport. LOL


The powerhead puts out 200 gph with no back pressure, but only about 80 gph with a foot of head, down to about 40 with two feet of head. I haven't run mine yet, since I'm still a few days short of having the tank set up. But, I can tell by how good it looks that it will be everything I ever dreamed of! (But, my dreams tend to be a bit dull nowadays.)


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## esarkipato (Jul 19, 2005)

Hoppy, is this up and running? results? pictures?

I'm in the "market" for a new reactor....need ideas.


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## Hoppy (Dec 24, 2005)

esarkipato said:


> Hoppy, is this up and running? results? pictures?
> 
> I'm in the "market" for a new reactor....need ideas.


Yes, it is now running and running quite well! I doesn't really collect a big CO2 bubble in the top as the sketch shows. It contains a swirl of CO2 bubbles, mostly confined in the middle of the water in the tube, but at the top it jumbles a bit and the bubbles get sucked in by the powerhead venturi loop tube. That generates mist which exits at the bottom. I use another powerhead with a sponge filter for filtration, which is at the opposite end of the tank, and that establishes water circulation which moves the mist all over the tank. I am still gradually increasing the bubble rate, so I'm not sure what it will look like when I decide I have it high enough. Below is a pic of it in the tank:


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## esarkipato (Jul 19, 2005)

Nice update, thanks


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## jaidexl (Sep 18, 2006)

Nice work, Hoppy.  This is something i wanna try.


Is there any reason the rio 50 wouldn't be a good choice for this? I want to limit my water movement, but not if it means inadequate churning of bubbles.


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## plantbrain (Dec 15, 2003)

There is no need to limit water movement, that is your friend, not the enemy.
The flow out of the bottom is slow and gentle with a rio 180, which is the typical pump I suggest for this.

Note the flow is coming slowly downward out of a 2" diameter pipe, this is not much flow even in a small tank like a 10 gal etc.

You have to get the CO2 to the plants and the only way to do that is by water movement. Diffusion alone in water takes a very long time.


Regards, 
Tom Barr


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## esarkipato (Jul 19, 2005)

I also plan on making one of these....the parts are now drying out. My only concern is the power or lack thereof of the powerhead I plan on using. I'll try to post pics here as well.


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## jaidexl (Sep 18, 2006)

Good points, Tom, thanks.


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## esarkipato (Jul 19, 2005)

I plan on using my [url="http://www.marinedepot.com/md_viewItem.asp?idproduct=HG10585]aqua clear power head 20[/url] for this setup, since I've already got one. Should I insert the "return" line back to the inlet of the powerhead, or attach it to the venturi on it?


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## Hoppy (Dec 24, 2005)

The "venturi loop" tube goes to the inlet of the powerhead. I drilled a hole in the inlet screen for the powerhead and poked the tube in there. You want the CO2 that goes up the loop to go thru the powerhead rotor and be chopped up into micro bubbles.


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## Aquamanx (Sep 28, 2006)

This is a Really cool post! Very inexpensive to build.. Although I wish I already had a powerhead to do this with, The only one I have is WAY too big for this! (aquaclear 802). I have been thinking of going with a DIY CO2 system for sometime now, just don't want to mess this up! Plus, I don't know how to find out what my CO2 level is in the tank. There must be some sort of test kit for this isn't there? I need as much info as I can get, plus, I would need to do this on a low-budget, as I'm in the market for a house & my girl would KILL me if she knew I was spending alot of money on "My Stupid Fish Tanks" again... LOL! (yeah, that's her talkin'... Only now one of the tanks, which happens to be the one that is planted, has HER Fish in it! LOL!)

Steve X.


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## Hoppy (Dec 24, 2005)

Aquamanx said:


> This is a Really cool post! Very inexpensive to build.. Although I wish I already had a powerhead to do this with, The only one I have is WAY too big for this! (aquaclear 802). I have been thinking of going with a DIY CO2 system for sometime now, just don't want to mess this up! Plus, I don't know how to find out what my CO2 level is in the tank. There must be some sort of test kit for this isn't there? I need as much info as I can get, plus, I would need to do this on a low-budget, as I'm in the market for a house & my girl would KILL me if she knew I was spending alot of money on "My Stupid Fish Tanks" again... LOL! (yeah, that's her talkin'... Only now one of the tanks, which happens to be the one that is planted, has HER Fish in it! LOL!)
> 
> Steve X.


Here is a thread on another forum about a pretty cheap, but relatively very accurate way to measure the CO2 in the tank: DIY Drop Checker - Aquatic Plant Central- aquascaping...a living art

Now, about the girl friend: when you have a choice between spending all of your money on this great hobby, and maintaining a girlfriend....well.....need I say more?


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## plantbrain (Dec 15, 2003)

One should be as passionate about their hobbies as they are about their spouses at a minimum.

Regards, 
Tom Barr


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## esarkipato (Jul 19, 2005)

> at a minimum


heheh 
:hihi:


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## Aquamanx (Sep 28, 2006)

Hoppy, Thanks for the info! I actually just read that the other day! LOL! I would be afraid of getting Chemicals in the tank... I think I'm going to hold off on CO2 untill I get the 45 set up & running... But, I do want to get things together for when I do get it going. I have Everything I need to get the tank running, But, I'm thinking I might hold off till I move to a new house. Instead of setting it up & then having to tear it down & set it back up & maybe losing some fish in the process... All I have to do is Poly the Stand, make a door, & build a Canopy (which I don't really need with the light I have...).

I'm pretty passionate about the Hobby, But, I'm Deffinately more passionate about my "Sexy Woman", as she likes me to call her... LOL! It's funny, cuz, alot of times when she introduces herself, she'll say "Hi, I'm X-Man's Woman"... LOL! My Friends get a kick out of it. But, she seems to like it. It's NOT Me that introduces her like that. I say this is My Beautifull or Sexy Girlfriend Kristy...

Have a Great Day!
Steve X.


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## dahcmed (Nov 2, 2006)

Hi! Just wondering, how you got the top side of the pump stuck to the glass (I was thinking that the provided suction cups are on the side, so these were not used). Pls advise.





Hoppy said:


> Yes, it is now running and running quite well! I doesn't really collect a big CO2 bubble in the top as the sketch shows. It contains a swirl of CO2 bubbles, mostly confined in the middle of the water in the tube, but at the top it jumbles a bit and the bubbles get sucked in by the powerhead venturi loop tube. That generates mist which exits at the bottom. I use another powerhead with a sponge filter for filtration, which is at the opposite end of the tank, and that establishes water circulation which moves the mist all over the tank. I am still gradually increasing the bubble rate, so I'm not sure what it will look like when I decide I have it high enough. Below is a pic of it in the tank:


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## Hoppy (Dec 24, 2005)

This is a pretty flimsy assembly out of the water, but the buoyancy of the water makes it easy to attach to the glass in the tank. I have two suction cups on the viewtainer part, and that is a very secure attachment to the glass. When I made it I siliconed a piece of plastic on the top of the viewtainer to help support the powerhead, but it came loose in the water - no effect at all on its stability. In retrospect I should have used a little Rio powerhead for a couple of dollars more, and it would be much more stabile even out of the water. Live and learn!


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## sunmiztres (Mar 20, 2006)

I made one of these but i used a 2.75 x 12 inch veiwtainer and it does great for my 80 gallon tank. I was running 12 bps and now i can get it from 7.3PH to 6.3PH in a couple hours using only 4 bps. Making the tube longer really helped out.


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## Hoppy (Dec 24, 2005)

Tom uses 4 inch long viewtainers, but I used a 6 inch one. I don't see the 4 inch one working with my powerhead. Even now the big bubbles swirl around under the viewtainer opening, captured by the swirling water I suppose. With a 4 inch one I think I would lose a lot of those big bubbles. The microbubbles do escape easily, which is what I wanted to happen. I think you are right that a l2 long tube would allow a much higher bubble rate, and you seem to have proved it.


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## fome (Sep 6, 2006)

stupid questions incoming!!

Where does the "burp hole" go? Or does the "burp" effect just come from the tube which feeds out of the viewfinder and back into the inlet?

What height do you have to make the hole that leads back to the inlet?

How exactly does the whirlpool effect occur?
- the inlet pulls water (or co2) from the outlet/viewfinder?


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## dahcmed (Nov 2, 2006)

fome said:


> stupid questions incoming!!
> 
> Where does the "burp hole" go? Or does the "burp" effect just come from the tube which feeds out of the viewfinder and back into the inlet?
> 
> ...


newbie here. But from what I understood, burp hole is for the air to come out of the viewtainer when the pump is off, so that not a lot of air is collected during that time.

The burp hole is on the opposite side of where the outlet (going to the pump inlet) is, about quarter of an inch below it. I think I saw a link before with the schematics.

Whirpool happens when the pump blows the water into the viewtainer on a 90degree angle, and the outlet tube (going to the pump inlet) sucks the water/co2.



By the way, I've created mine from a gravel cleaner (can't find the viewtainer here). Instead of putting the pump on top and attaching the elbow inside, I drilled a hole on the top side where the pump's outlet fits nicely. This way the input from the pump is still at a 90 degree angle and I can still use the suction cups that came with the pump. Then attached it to the right corner of the aquarium.

My only mistake was being afraid of the current that it might produce in my 15g so I took the 280L/hr pump, realizing at the end that I could have gotten something stronger and it wouldn't have created any additional current. But with 2 bps from my DIY CO2, I'm getting a lot of pearling and a lot of growth anyways, so it's ok for me.


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## Hoppy (Dec 24, 2005)

Putting the powerhead outlet in the side of the plastic cylinder (viewtainer) is an interesting idea. The suction cups on the powerhead then do what they are supposed to do, and you don't depend on the thin, flexible viewtainer to hold everything up. I like the way this thing works so well that the next time I make one I may get a piece of acrylic tubing the right size and use that much more robust tube in place of the viewtainer.

The problems I have had so far with mine are:
The use of silicone sealant to hold part of it together - silicone doesn't adhere well to the viewtainer or to the powerhead.
Cleaning the viewtainer tube is difficult, and it does get a brownish slime growing in it eventually.
The assembly is flimsy when out of the water, so trying to clean it without it falling apart is hard for me.

This basic design does work very well, so I'm willing to spend a bit more by using a stronger plastic tube, applying dahcmed's idea of mounting the powerhead on the side and not the top, and getting a smaller Rio powerhead to use. I think those changes will make it just what I want.

Tom has been saying, don't be afraid to experiment with this, try new arrangements, use different materials. It isn't rocket science - it is just making the parts do what you want them to do. The basic idea is pretty simple.


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## esarkipato (Jul 19, 2005)

For mine....I used the silicone to attach the 90 degree bend powerhead attachment to the reactor. That way, I can just slip the powerhead on and off with little hassle. 

On the downside, one of my suction cups did not stick to the reactor plastic very well, so I'm down to one. I guess just another downside to DIY.

I agree that the powerhead might as well be mounted horizontally. Especially after the suction cup fiasco


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## treetom (Feb 11, 2011)

Where can you get the plans for this now? The link does not work anymore.


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## Batt4Christ (Apr 24, 2011)

Sorry to again revive an old thread - but I too would love to see the "plans" to build this. My Hydor diffuser/reactor just isn't cutting it. I can barely get up to 20ppm of CO2 running way too manny bubble per second.


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## Hoppy (Dec 24, 2005)

Wow! This is an old one. This link still works http://www.aquaticquotient.com/forum/showthread.php/13643-Tom-Barr-s-DIY-Internal-Reactor-w-venturi


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## plantbrain (Dec 15, 2003)

I'm not that old ....am I?


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## wkndracer (Mar 14, 2009)

plantbrain said:


> I'm not that old ....am I?


Bwahahaha! yeah you are (and it happened overnight)


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## jdatwood (Dec 14, 2014)

Has anyone found a cheap source of clear PVC recently? I'd really like to build one of these with clear PVC


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