Dual venturi DIY External CO2 reactor

[Tom Barr]

This unit cost about 20$ due to using Clear PVC housing, you can use solid 2" pipe if you wish.

You can find all the parts at any Orchard Supply Hardware or Home Depot.

Two: 2" slip to 1/2 threaded bushing
Two: threaded 90 elbow 1/2" barbed
About 10 Bioballs if desired
12" of rigid 3/16" air line
PVC glue
3/16" drill bit
Drill
Powerhead or canister filter etc

This works very well in sump areas also.

[Tom Barr]

So assembly is very easy as are drilling two to three 3/16" holes.





As you can see from the pictures, we drill two holes on the top.
You insert a 12" long piece of rigid 3/16" tubing and glue the top and bottom with the PVC glue. This seals it in place and is the CO2 inlet.
I chose clear PVC(available through Aquatic Ecosystems) so I could use this like a bubble counter. I can see how many bubbles per second are going into the reactor.

The other hole can be used for two different functions.
It merely has a 3 " piece of rigid air line tubing inserted and glued in place.
It can have a simple ball valve(irrigation drip valves work well here) and allows you to remove any gas build up manually. It also allows control of the gas being sucked out if you want to use this for degassing the chamber with venturi suction.

This prevent any gas build up inside the venturi External reactor.

Optional:
Another hole can be drilled, about two inches from the top of the reactor. This can be fed to the suction side of the powerhead to degas the chamber once the gas builds up to this preset level.

The usefulness of this method is incredible. Degassing the chamber via the venturi
loops allows the chamber to have much reduced gas lock and backpressure, as well as providing a fine gas mist once the gas buld starts affecting efficiency.

This waste some gas later in the day but adds the mist directly to the tank and plants. The effect is phenomenal.

This design is based on a closed loop like the internal venturi reactor.

Both are 100% efficient until the gas starts to build up and then it starts degassing the bubble into mist and ejects it out into the tank later in the day.

[FacePlanted]

So do you only use one or the other of the "venturi outlets" (the one on top vs. the one on the side)? Or can you use both of the short airline pieces to create 2 venturi loops?

Do you only need the second outlet 2" down if you are using the smaller top outlet as a relief valve?

Thanks.

-Mike B-

[Tom Barr]

You use only one of the venturi holes generally.

No need to use the lower one if you use the upper.

The article and pictures are not done yet, so I'm going to move some post around here a bit.

Regards,
tom Barr

[FacePlanted]

Is there a way to construct a venturi loop without the placing the end of the loop on the intake side of a canister filter/pump/impeller? Can the end of the venturi loop be fed into somewhere after the canister filter/pump? Somewhere on the return line?

I ask this because I am using the pressurized Rainbow Lifeguard Modular Filters with a Quietone 3000 pump and I dont think that the microbubbles will be able to be forced through the micron pleats in the mechanical module. And that it would just create a bubble that I would need to bleed out of the module.

Is there some way I can still use the venturi loop with this type of setup/filter? Or will it only work with the suction that is created by the intake of the pump and smashed up by the impeller?

Thanks for your help and patience.

-Mike B-

[mrkookm]

What would we ever do without you! I just built a reactor based on your design and I am veryyyy happy with the results! I get a lot more mist I can barely see 'have to go up real close and look real hard' perfect bubble size. I even like hearing the water inside churning sounds as if co2 and water is getting truly mixed in and my plants are telling me they love it! Crazy pearl even more than before!!

I have this setup on a 90g w/ sump. My reactor sits in the sump with is own pump feeding water in and the misty water output hose I have inserted into the bulhead that feeds my system pump so nothing is wasted or circulated in the actual sump.

I have used many reactors in the past and this is the only one that has ever worked well for my demanding system!

[Tom Barr]

This should outperform every other brand or reactor out there.
Most have no clue as to the venturi and mist idea.

Those are my designs.
The internal reactor is similar.

Degassing the gap inside helps a great deal in the effectiveness.

Regards,
Tom Barr

[mrkookm]

Degassing the gap inside helps a great deal in the effectiveness.

I agree with you 100% on this! Simple but very effective....keep the ideas rolling TBarr!

The output coming from my reactor gives a new meaning to what we call 'misting'

[Tom Barr]

Well, it does get more out of the misting and keeps it running full time when the reactor is on.

The good thing is that it's less wasteful than the internal method.
Some collection and coalescence occurs in the sealed chamber as well as recirculation to a much greater extent than the internal design.

You can also set the desired levels of recirculation to increase or reduce the misting by adjusting the valve on the venturi loop. You can also place the venturi inlet hole higher or lower depending on your goal.

I'll bring this unit to the Local SAPS club meeting this Nov to show folks how to make it and so they can see it up close up and touch it etc.


This is the entire reactor:


This is the option to use the lower venturi intake:



This is the option to use the top venturi intake method at about 1" depth for the gas collection bublle vs 3" in the above example:



Missing from pics are the venturi ends are a ball valve irrigation drip to control the flow and also to turn off the Gas and seal the end when not in use.

Note: you can modify the AM 1000 and the Dupla reactors by making a venturi loop to the powerhead or pump driving the flow through.

For 10-15$, it's hard to beat this product and design.
This is good to about 180 gallon or so with 400-500gph.

Regards,
Tom Barr

[hani]

HI, just woudring how the degassing works? will the extra gas go back through the intake of the pump and goes back to the reactor again?
hani