# List of CO2 Diffusion Methods



## karatekid14 (Jan 16, 2011)

Hello, I want to compile a list of CO2 diffusion methods to help people choose the best method for their situation. I am not an expert on CO2 diffusion, nor have I tried all of the suggested methods but from my own research this is what I have gathered. If anyone has thoughts or more ideas to add, please feel free to comment, and I will add to the list or change it if there are mistakes.

*What Are We Trying to Achieve with CO2 Diffusion?*

-When CO2 is injected into water it turns into H2CO3, carbonic acid 
-carbonic acid is what lowers your pH, as an acid has a pH<7​-The longer the CO2 stays in the water the more that dissolves
-The smaller the CO2 bubbles, the more CO2 that dissolves, as small bubbles have a greater surface area to volume ratio than large bubbles.

-*Example: Ratio of Surface Area to Volume*
1 cm cube (1x1x1) 
Surface Area:	6 cm sq.
Volume: 1 cubic cm	
Ratio: 6:1

2 cm cube (2x2x2)
Surface Area:	24 cm sq.
Volume: 8 cubic cm	
Ratio: 3:1​
*Common Question*: “What is the best diffusion method for paintball CO2?”

The following methods will work with all manner of paintball systems. However, if the paintball system you are using consists solely of an ASA shut off with a needle valve then you cannot change the working pressure. I would not recommend using this system as it can be dangerous, and I’ve found it to be more difficult to dial in the correct bubble count.

*Question:* “What is the best diffusion method for DIY CO2?”

I am not sure whether DIY CO2 will work with all of these methods. I am fairly certain it will not work with the Atomic diffuser because DIY CO2 cannot produce the pressure needed to run the diffuser. 
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*Diffusion Methods*


*Ceramic:*

*Glass:* They come as inline (Cal-Aqua) or more commonly in-tank. CO2 fills up the chamber below the ceramic. Ceramic has tiny pores, which the CO2 pushes through. Some glass diffusers produce a much better mist than others. It really depends on the quality of the product.

In-tank









Inline (Cal-Aqua)










*Atomic:* They come as inline or in-tank. Atomic diffusers require a working pressure of at LEAST 30 PSI because the pores on the ceramic are much smaller and the CO2 has to be forced through. They usually produce a very fine mist.

In-tank









Inline









_*Do not scrub ceramic diffusers, it may damage them and the bubbles produced may increase in size._


*Reactors:*

*Rex Grigg:* You may either buy a Rex Grigg style reactor or build one yourself from PVC components. Water passes from the canister filter through an entrance at the top, then passes through the diffusion media and exits at the bottom. The CO2 also enters at the top and passes through the media, breaking down into smaller bubbles, before exiting. 

Aquamedic









DIY










*Cerges:* There is one commercial system similar to Cerge’s, the rest are DIY. Cerge’s reactor uses a housing from a reverse osmosis unit, which has an entrance at the top that water travels through, then down a PVC pipe to the bottom. The exit is located at the top, so the water must swirl all the way from the bottom before exiting. The CO2 also enters at the top so that it spends the maximum amount of time in the water. It travels down the PVC pipe and swirls in the water, dissolving before exiting. 

Insta









DIY









_*Why are reactors effective? Both of these designs allow the CO2 to be broken down and give the CO2 the maximum amount of time in the water to dissolve. Reactors are the most efficient way to diffuse CO2, with nearly 100% dissolving._


*Other:*

*Ladders:* Large CO2 bubbles enter at the bottom, and rise through the ladder. This gives the CO2 more time in the water to dissolve.










*Pump/Powerhead:* The CO2 line is inserted into the pump intake, where the impeller chops the bubbles into smaller bubbles. This method can be used either in-tank or inline with a manifold. Some attach a tube to the pump when in-tank to keep the CO2 recirculating.

Pump









Tube attached










*Needle Wheel:* This method uses a pump that has an impeller with many fins, or a furred impeller, which helps break the CO2 bubbles down into a mist. They are most often used inline.









_*Do not inject the CO2 into a canister filter, as it is possible that bubbles could be trapped in the media and eventually form a large gas pocket. If this happens and the filter runs dry, the motor will most likely be damaged. If using an inline pump diffusion method, mount the pump after the filter._


*Mazzei:* Pressurized water enters the inlet and is constricted toward the injection chamber, where it changes into a high-velocity stream. The increase in velocity through the injection chamber creates a decrease in absolute pressure, which creates a vacuum, and draws CO2 through the suction port and into the water stream. As the stream is diffused toward the injector outlet, its velocity is reduced and it's reconverted into lower pressure. This creates a very fine mist of CO2.









Assembly









_*Providing the correct amount of flow can be difficult. Research this before buying a random venturi._


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## oldpunk78 (Nov 1, 2008)

Water flows through a standard reactor from the top and out at the bottom. I think you wrote the reverse of this.


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## karatekid14 (Jan 16, 2011)

Thanks for catching that!


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## OVT (Nov 29, 2011)

Great write-up! 

v2


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## exv152 (Jun 8, 2009)

Nice write-up, what about the mazzei injector method, and furred blades in addition to chopped blades?


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## MrSlumpy (Jan 4, 2013)

Don't forget this nice cheap option:

Amazon.com: Gulfstream Tropical AGU00528 Ista Max Mix Co2 Reactor for Aquarium, Medium: Pet Supplies

Also, paintball tanks can be connected to any "proper" regulator using an adapter, right? Seems misleading to lump any paintball system into the same category as the completely non-adjustable ones. For example, I'm using paintball tanks to run a GLA atomic v3 regulator (with a cga320 adapter), and the bubble count is pretty easily dialable.


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## karatekid14 (Jan 16, 2011)

I added the Mazzei method, and rewrote the paintball section. Is that reactor basically a commercial Cerges? I don't think I am going to add every product that is a little bit different to the list, only distinct categories. 
Thanks for the feedback


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## norbot (Jan 5, 2013)

Great job on this! It's nice to have consolidated info, it should be helpful to anyone wondering what co2 method to use.

What about in-tank reactors? I've never used one, nor do I know if they are popular, but I've read they work well and most are diy using a gravel vac tube with powerhead.

The main drawback is that they're ugly, but they are cheap and easy to make


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## MrSlumpy (Jan 4, 2013)

karatekid14 said:


> Is that reactor basically a commercial Cerges?


Yes, you may just want to mention that Cerges style reactors are available commercially. (Although the Ista is the only model I've personally come across.)


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## karatekid14 (Jan 16, 2011)

Added gravel vac and insta


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## exv152 (Jun 8, 2009)

This is what I meant by furred blades. It's common for those using pumps to not just chop the blades, but fur them up too, very effective method of breaking up co2.


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