# DIY CO2 Generator Soup



## essabee (Oct 11, 2006)

Has anyone tried to adding macro and micro fertilisers to DIY CO2 soup?

Has anyone tried adding a little milk to the DIY CO2 soup?

When I used to bake my own bread, I would start the yeast with tepid milk before making the dough. I intend to start my DIY CO2 generator the same way, unless I hear something against it.

I am wondering ……….. if adding a bit of the aquarium plant fertiliser would help the CO2 generation. They do add a lot of N fertilisers to the mushroom substrate. The mushroom substrate is mostly organic plant waste, containing a lot of plant nutrients.

Next comes the question………… at what ph to start the CO2 generator soup? Has anyone played around with these parameters?


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## wiste (Feb 10, 2006)

> Has anyone tried adding a little milk to the DIY CO2 soup?


The Nyberg CO2 method suggests protein powder. Powdered milk is protein powder.


> http://www.aquaticplantcentral.com/...berg-co2-method.html?highlight=yeast+nutrient





> I am wondering &#8230;&#8230;&#8230;.. if adding a bit of the aquarium plant fertiliser would help the CO2 generation.


Ammonium sulfate is yeast nutrient which combined with the protein powder will produce alot of CO2 quickly. The attached post indicated they used urea. These methods will boost the output.
http://www.aquaticplantcentral.com/forumapc/showpost.php?p=84283&postcount=17



> Next comes the question&#8230;&#8230;&#8230;&#8230; at what ph to start the CO2 generator soup? Has anyone played around with these parameters?


I am not sure about what PH to start the CO2 generation. However, the above mentioned method suggests adding baking soda to buffer the PH to prevent the solution from becoming to acidic.


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## redstrat (Apr 3, 2006)

some people add some baking soda to buffer the Ph a little but I dont really see the purpose in adding anything else like you mentioned. I would be concerned about the milk getting nasty over the time the Yeast solution is being used. I dont really think plant ferts would do anything either because the yeast solution never ever comes in contact with the aquarium water and its sole purpose is to produce CO2 as a byproduct of the fermentation process, these chemicals probably wont provide any benefits there. The Yeast needs water and sugar to ferment and produce CO2 the baking soda helps keep the PH high enough to prolong the life of the yeast because the PH drops over time. I have heard of some adding gelatin but I'm not completely sold on it either. 


just my two cents. 


another question you have to ask, am i'm putting to much into DIY should I just take this money and effort and put it into a pressurized system to save the maintenance and CO2 fluctuations


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## essabee (Oct 11, 2006)

I know and I understand................ We are decomposing sugar to make CO2 and not growing yeast as a product, but then if we do grow the yeast we will have higher CO2 production rate, without having to add more yeast, and the period of production will fall. As to the ph; what is it that stops the production---- alcohol or acid? If it is the acid then buffering the soup appears to allow you to make it richer with sugar and if it is the alcohol we can only put enough sugar which will cause the level of alcohol which kills the production of CO2.

The exercise is to get the maximum production of CO2; I would have no problems if I could afford pressurised CO2 system, but then where I live refills are not available for love or money, even if I do acquire the equipments from elsewhere.


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## Squawkbert (Jan 3, 2007)

If you want to jump start CO2, you could use the yeast packaged w/ a little ascorbic acid ("Rapid Rise"), I wouldn't be inclined to add anything more. pH swings don't kill yeast, I'm pretty sure it's the ethanol build up. By volume, using 3 parts water to 1 part cane sugar will result in (bread) yeast starting to die off due to ethanol poisoning right about the time the sugar runs out (etoh would be between 10-12% by volume).

Na-Bicarbonate would probably curtail CO2 production, at least initially, as yeast does not like Na ions...

I'm still working out optimum starting amounts for yeast...


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## essabee (Oct 11, 2006)

Squawkbert said:


> If you want to jump start CO2, you could use the yeast packaged w/ a little ascorbic acid ("Rapid Rise"), I wouldn't be inclined to add anything more. pH swings don't kill yeast, I'm pretty sure it's the ethanol build up. By volume, using 3 parts water to 1 part cane sugar will result in (bread) yeast starting to die off due to ethanol poisoning right about the time the sugar runs out (etoh would be between 10-12% by volume).
> 
> Na-Bicarbonate would probably curtail CO2 production, at least initially, as yeast does not like Na ions...
> 
> I'm still working out optimum starting amounts for yeast...


I was told by a home beer brewer, that sometimes the fermentation would get stuck and he would have to add diammonium phosphate to get it going.


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## redstrat (Apr 3, 2006)

your probably best off finding better yeast than bakers yeast, such as wine making yeast I've heard it lasts longer and produces more CO2 pound for pound. Granted I haven't personally tried it mainly because its not the easiest thing to find and it supposed to cost more.


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## onemyndseye (May 12, 2006)

I've never been able to prove any of this works...

But I have read considerable information about yeast including their metabolic requirments.

The do in fact need more than just sugar (glucose) as wiste had sugested to sustain life... but the question is to what degree.... I have tried adding alittle liquid hydropnic solution or quarium plant ferts to experiment but I didnt notice an obvious gain.... Not that I was documenting my results.

I have also read some reports that Hobbyist made some sort of Toxic cocktail when trying to get too fancy with their yeast mixture (i.e. plant fertz)... also have seen nothign first hand to confirm.

There is alot of great information about Yeast floating around on the Net as the yeast bacteria is certainly one of the most research beasties on the planet...

Personaly, I feel that trying to provide the optimum nutrition for the yeast is a pipe chase... as the results for our applications will probably not show much (if any) of an increase....

The facet that intrigues me is that yeast fail to produce ethanol in AEROBIC enviroments.

I know this has been discussed from time to time... But looking at the chemical equations, there just has be a way to make this work for us.

I dont remember the exact equations but they look something like:

Aerbiosis:
1 C6H12O6 = 6 CO2 + 2 H20

Anaerobiosis:
1 C6H12O6 = 4 CO2 + 2 H20 + 2 ETOH
(Sugar)-----------------------------(Ethanol)

Take Care,
-Justin
One Mynds Eye


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## Kelley (Aug 27, 2006)

Hi Essabee,
I am a geneticist who works with yeast as an experimental system. We grow our liquid cultures with two types of media. We use a rich media called YPD for faster growth. It contains glucose, yeast extract and peptone. The last two ingrediants are commercially available to researchers (and expensive!) and provide the yeast with amino acids and trace nutrients. We also use a synthetic media composed of glucose, ammonium sulfate, yeast nitrogen base (commercially available and expensive!) and individually added amino acids depending on a particular yeast strain's requirements. Our strains prefer to fe grown at 30 degrees C with constant aeration in the form of approx. 175 rpm of shaking. 

Maybe you could try to replicate some of these conditions at home. You could perhaps try 2 or 3 grams of non-fat dry milk per liter along with your sugar. If you do this you MUST find a way to sterilize everything first. You can boil the reaction vessel and pass the media through a 3 micron filter or even boil it. If you can find a way to aerate your cultures either by shaking or by stirring, you will increase production. Also, try to keep things a little warmer. (Probably not an issue for you!) Then the only limiting factor will be when the culture becomes saturated and the nutrients are exhausted. Then you will have to change out the media and start again. 

I don't know if any of this will help you provide more CO2 to your aquarium. I do know that this is the best way to keep lab strains of yeast happy and growing. Good luck!


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## Purrbox (Jun 1, 2006)

I used Red Star Champagne Yeast when I was still doing DIY CO2. It worked quite well and the reaction would easily go 3-4 weeks.

One thing that I've heard great results on but never tried myself is using molasses and protein powder as a part of the mix. Apparently you can get just as good of results if not better using these additives with regular yeast, as you can when switching to the Champagne Yeast. It'd be quite interesting to see how long a mix would last when combining both.

I just looked up the recipe as posted by Zezmo on AquariumAdvice.
2 Liter Bottle
2 cups Sugar
1 tsp Baking Soda
1 T Molasses
1/4 cup Protein Powder
2 drops dechlorinator
fill with tepid water to 2" below top

Zezmo reported that this mix lasts 4-6 weeks.


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## essabee (Oct 11, 2006)

Hi Kelly

Since you are into research with yeast, I hope you would clarify certain querries.

1) Does the concentration of ethanol produced stop the further fermentation, or is it the fall in ph? (sugar being still available)

2) What available variety of yeast continues fermentation while stoppage of fermentation has occurred in other yeast varieties?

3) Is the 175RPM shaking of yeast culture done to reduce the CO2 concentration in the yeast culture?


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## Kelley (Aug 27, 2006)

I started thinking a little more about your problem last night and i don't think that vigorous shaking will help you. We do it to increase oxygenation in our cultures, as well as to exchange out the CO2. We keep our culture flasks covered loosely to allow this sort of aeration. I still think that a bit of gentle and continuous stirring would help you. The yeast has a tendency to sink (flocculate is the technical term) and it has less access to nutrients. 

I believe that high EtOH concentrations are more detrimental than pH decrease. Do try the wine-making/brewing yeast, if you can get your hands on some of it. I have friends that have tried it in there set-ups with success and the logic behind this makes sense to me. 

Of course no matter what you do, the more often that you change your culture, the more consistent this all will be. 

Good luck!


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## essabee (Oct 11, 2006)

Hi Kelley
Got most of my answers, thanks.

You missed the first---1) Does the concentration of ethanol produced stop the further fermentation, or is it the fall in ph? (sugar being still available)

And I would like to ask you another---2) Can I use a mix of different yeasts?


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## Kelley (Aug 27, 2006)

The high concentration of Ethanol is more detrimental than the reduced pH. It essentially kills and/or halts the growth , hece the respuiration of the yeast. Still, I don't think it would hurt (and might help) to buffer your media. Yeast prefer a phosphate buffer to a bicarbonate buffer. You could add K2HPO4 and KH2PO4 (perhaps about 1 gram each per liter?) to buffer the system a bit. 

As for mixing strains of yeast, I don't have a lot of knowledge of commercially available yeasts outside of what I know from baking bread. The strains I grow in the lab are nothing like you would want to use. They are intentioanlly very sickly compared to the genetically supercharged strains used for baking and brewing. It won't hurt a thing to mix strains in your cultures. However, the most robust strain will always outcompete the weaker ones. 

The brewing/wine-making strains are the best option, by far. They are far diverged from wild yeasts and have been highly selected to withstand elevated concentrations of Ethanol.


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## vic46 (Oct 20, 2006)

Start the yeast in a 1/2 cup of water at 100F and 1/2 tsp sugar. Allow to sit for 10/15 minutes and then put in generator. Make sure generator is warm. The sugar helps the yeast start as that is what yeast "eats". Use a resilient yeast such as Brewer's Yeast or a champagne yeast. They are far more tolerant of the ethyl alcohol produced by the fermentation process.
Cheers;


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