# Whats the biggest DIY CO2 bottle you can make?



## boognishmofo (Sep 26, 2011)

I was curious what the biggest bottle anyone has ever used. If you make a bigger bottle and bigger batch will it last longer or produce more gas?


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## boognishmofo (Sep 26, 2011)

Does anyone know? A bigger bottle, say 2 gallon will that produce longer than a 2 liter or will it produce more gas in the same time frame?


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## wi_blue (Apr 5, 2005)

I'd bet that the larger the bottle the more potential for CO2 output. Though I doubt that it would last longer.

Sent from my ADR6300 using Tapatalk


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## CuLan (Oct 22, 2008)

I used 3-liter soda bottle before. To compare to 2-liter bottle, I used the same amount of yeast with 150% of the sugar and 150% water. The intention was to get proportional increase in time (last longer). That is it would produce the same amount of CO2 (bubble count) and last 50% longer (3 weeks instead of 2 weeks). The result: No change. Unscientific conclusion: Most of the yeast can probably only last for 2 weeks in that environment, does not matter how much more water or sugar added.


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## TAB (Feb 7, 2009)

I built one out of some 4" abs and fittings, it was about 24" tall so a little over a gallon. Lasted about 3 weeks.

let me see if I can find the pics.


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## Zapins (Jul 28, 2004)

I dont think a bigger bottle would last longer if you put all the ingredients in the same ratio as a smaller bottle. I think someone found that if you add some type of gelling agent in the bottle it will last longer.


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## boognishmofo (Sep 26, 2011)

Yeah I've read the gelatin recipe. Too much trouble for me. I had started to construct a container out of PVC it was the 2 ft I think 6" diameter peices they sell precut at home depot. I capped the bottom and put a screw on lid on the top. It hold about 5 quarts. I havnt decided if it was worth completing. I might use it to make a fluidized bed filter instead. Has anyone built a bigger one with increased recipe over all. I would love to see those pics Tab if you can. What is abs?


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## TAB (Feb 7, 2009)

the black plastic pipe, normally used for drain lines in the US.

I tired to find the pics, but I must have deleted them.


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## geeks_15 (Dec 9, 2006)

I have a friend who brews his own beer. He rigged his ~5 gallon fermentation canister up to his 55 gallon aquarium...and all the fish died. He swears nothing but gas got into the aquarium. 

?????????


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## Elrodg (Sep 17, 2011)

I have five two liter bottles daisy chained together with more water added to each bottle. All five meet in a pressure chamber made from an aluminum still tank. It holds a constant 40 lbs of pressure.


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## Elrodg (Sep 17, 2011)

The trick is to reduce your output area with each bottle. And a gas separation tank made from a 20oz bottle. This all bleeds into the pressure tank. A needle valve setup will add extra pressure by restricting flow but you have to have a tank of sorts that can handle more pressure. I use a strong sugar mix with a half tsp yeast in the first bottle and reducing mix as you go down the chain.


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## boognishmofo (Sep 26, 2011)

I was trying if possible reduce the amount of 2 litre bottles I use. Thought maybe if big enough I could use one container.


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## Elrodg (Sep 17, 2011)

Well I made a four gallon one out of an old water jug. (plastic or glass works). Hard part is finding a stopper. But if you look for chemistry supply sites you can find one.


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## boognishmofo (Sep 26, 2011)

Elrodg said:


> Well I made a four gallon one out of an old water jug. (plastic or glass works). Hard part is finding a stopper. But if you look for chemistry supply sites you can find one.


How long does it last?
What size tank? 
What is your ppm?
How large of a recipe?

If from what I understand correctly, the larger volume of water used the longer the yeast can stay alive. Is this right? You could add more sugar half way though the phase to feed it again. 
I was looking at my dogs water jug, the same I believe your talking about.


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## Lizid (Oct 26, 2009)

Hmmm guy this is a very interesting I have just setup a DIY system so I am also very interested in what's being said, but my next question I need to ask is, at what point doest it just not make sense to run DIY?

I will keep following this thread as I am really thinking about the same problems...


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## tokyo (Apr 23, 2010)

To prolong the production there are a few things I would try:

1. Decrease the rate of alcohol/CO2 production. There are three main ways to do this; reduce temperature, reduce the amount of yeast initially added, reduce the amount of oxygen in the mixture(oxygen = reproduction).

With a reduced rate of production you would need to increase the volume of the mixture, keeping the same ratio(water:sugar:yeast) in order to maintain the amount of CO2 produced.

2. Use a yeast with a higher alcohol tolerance. It is the alcohol that builds up in the mixture which kills the yeast. So a yeast with a higher alcohol tolerance would allow more alcohol to build up before dying. Regular bread yeast has an alcohol tolerance of around 10-12%(if I remember correctly). There are specialty brewing yeasts that have alcohol tolerances as high as the mid 20s, possibly higher. The downside is that they tend to be a bit pricier than the bread yeast that you can pick up at any grocery store.

3. Slow release food. Basically, the gelatin method, as has been mentioned previously, allows sugars to slowly be made available to the yeast rather than having an unlimited amount available from the start. This another method for decreasing the rate of production. I'm not sure why I separated it from the others.

I think if you used all or most of these methods you could extend the life your DIY CO2 batches considerably. But it would most likely take some experimentation.

.02


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## SlyDer (Jul 11, 2007)

Several years ago I used a 3 gallon jug on my 55 gal planted. The result was increased co2 output (what i needed at the time).However, I never could get it to last more than 2 weeks before the production got so low that it was no longer worth it.


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## D9Vin (May 12, 2011)

I have been following this thread for a while, so I suppose it's time to throw my 2 cents in the bucket. I think, and this is total theory, the reason you can only get the mix to last around two weeks, and the reason the gelatin method works, is you must consider yeast is alive and reproducing. If there is plenty of food, there will inevitably be plenty of yeast, regardless to the initial yeast amount. If you made a 55 gallon drum diy unit, and kept the same proportionate amount of sugar, but only put in a teaspoon of yeast, it may take longer to really get going, but eventually as the yeast population grows, you are just going to produce an insane amount of co2 over maybe a 2 1/2 week period. I am guessing the gelatin restricts the movement a bit and thereby the access to the sugar.


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## tokyo (Apr 23, 2010)

D9Vin said:


> ...yeast is alive and reproducing. If there is plenty of food, there will inevitably be plenty of yeast, regardless to the initial yeast amount. If you made a 55 gallon drum diy unit, and kept the same proportionate amount of sugar, but only put in a teaspoon of yeast, it may take longer to really get going, but eventually as the yeast population grows, you are just going to produce an insane amount of co2 over maybe a 2 1/2 week period.


The yeast only reproduces while oxygen is present. This is why limiting the oxygen as well as the initial amount of yeast should work to slow down alcohol production and therefore extend the life of the yeast.


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## D9Vin (May 12, 2011)

How would you limit the oxygen? Is it as simple as filling the bottle up more?


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## tokyo (Apr 23, 2010)

Yes, I would say reducing the volume of air in the container would be the simplest way to limit oxygen.


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## essabee (Oct 11, 2006)

How big?! Browse :-

http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/45030-co2-madhatters-diy.html


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## nkambae (Nov 6, 2007)

A larger container will not necessarily correspond with a longer production period unless you start out with a smaller amount of yeast. It then takes longer for the yeast to get up to maximum production. The yeastie beasties will only produce CO2 and alcohol as long as there is food (sugar) and O2 or until the alcohol content becomes lethal to them. As was mentioned previously, different strains of yeast tolerate varying levels of alcohol. Baker's yeast will tolerate about 6-10% (depending who you believe), brewers yeast around 8%, wine to 12-14%, and champagne yeast to 18% or so.

As I see it, the real issue with diy CO2 is consistency of production instead of longevity. Fluctuating levels of CO2 in an aquarium with high light and commensurate demand for ferts and carbon is almost as bad as no CO2 at all. My best results with diy came when I used three bottles manifolded together. I would change one bottle per week assuming that I would get no more than about two weeks of strong production from any one culture (based on personal experience). I always activated my champagne yeast with warm water in order to get good production within 24 hours. This method gave me one bottle approaching peak production, one bottle at peak production, and one bottle on the decline from peak production. I found it worked well. At least the plants looked good and there weren't any issues with algae.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC374775/?page=1

http://www.home-winemaking.com/winemaking-1b.html

I used two liter bottles on my 38 gallon and one liter bottles on the smaller tanks I had. I did try a one gallon container but it was rather cumbersome. It produced ALOT of CO2 but only for about two weeks before production declined. I have since gone to pressurized CO2 as I found it difficult to change the bottles in a timely fashion when I was out of town for work. Good luck.

stu


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## boognishmofo (Sep 26, 2011)

Lizid said:


> Hmmm guy this is a very interesting I have just setup a DIY system so I am also very interested in what's being said, but my next question I need to ask is, at what point doest it just not make sense to run DIY?
> 
> I will keep following this thread as I am really thinking about the same problems...


I would say, when you are spending more money on sugar and yeast than it would cost for a co2 setup and refills then you def would be better running pressurized. For me this is what I HAVE to do for now. I have a baby on the way and in between jobs. Luckily I work as a chef and have easy access to cheap bulk yeast and sugar. 
Everyone says there is no point doing diy on anything larger than 30 gallons at the most. I find and have experimented with and without on my 55g and have seen a huge difference adding even just three 2litre bottles but have gotten my co2 to 22ppm with 4. So thats 8 cups of sugar every two- three weeks. I think most grocery stores sell a 25lb bag of sugar, probably somewhere around $15. That is 56 1/4 cups so it will last about 3 1/2 months. As you can see it quickly adds up. At that amount your looking at $60+ - a year in just sugar. Yeast is usually the cheap part, I get a 1lb bag for around $10 and it last a long time.

I have a friend that had a full co2 tank for his restaurant coke machines. I tried to rig it with a regulator from an air compressor and a needle valve for finer control but it didnt work. I was talking with the Coke guys the other day and asked (hint,hint) you guys know a cheap place in town to get a co2 regulator? They told me a couple places, and then 30 minutes later they were gone and there was a brand new regulator lying on the floor by the back door. Unfortunately I asked my buddy if I could use the tank again and he said he was using it now. I should be able to find one pretty easy though being in the restaurant business. 
Conclusion, If you can afford it and have a bigger tank, go with the pressurised system. I will probably go with the regulator I scored and a tank I can get from a restaurant for my 55. Slowly I will gather the stuff to do a paintball setup on my 39 and 29 gallon and might just stay with diy on my 10g.


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## boognishmofo (Sep 26, 2011)

essabee said:


> How big?! Browse :-
> 
> http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/45030-co2-madhatters-diy.html


Awesome, this was exactly what I was looking for. I searched and searched and could not find anything. Unfortunately, for everyone else this would be very expensive to maintain.

Why exactly does this moonshiner provide you with these materials? I dont understand why it would be beneficial to him at all.

I live not too far from the "so called" moonshine capital of the world right outside of Nashville Tennessee.


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## boognishmofo (Sep 26, 2011)

tokyo said:


> The yeast only reproduces while oxygen is present. This is why limiting the oxygen as well as the initial amount of yeast should work to slow down alcohol production and therefore extend the life of the yeast.


Wouldnt the only O2 available be what is in the water once there is pressure and all the o2 is pushed out of the bottles and airlines.


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## boognishmofo (Sep 26, 2011)

essabee said:


> How big?! Browse :-
> 
> http://www.aquaticplantcentral.com/forumapc/diy-aquarium-projects/45030-co2-madhatters-diy.html


What size tank is this for? Its got to be big, I would think. What is your levels ppm?


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