DIY Plant CO2 Mix Experiment

catsma_97504
Member
Instructions for setting up DIY CO2 System

As I have been experimenting with different mixes to add to my DIY CO2 bottles, I thought I'd start this thread to document my findings.

Feel free to add your personal triumphs and failures too.....

Conversion Chart for those outside the US:
1 cup = 8 fluid ounces = 236.59 ml
2 cups = 16 fluid ounces = 473.18 ml

1/4 tsp = 1.23 ml
1/2 tsp = 2.47 ml
1 tsp = 4.93 ml

Option #1
*1/4 tsp yeast
*1/4 tsp baking soda
*2 cups sugar

When I begun using DIY CO2 about 9 months ago, this was the primary recipe I found on the net. This mix lasted 10-14 days and seemed to be decent at producing a steady stream of CO2. But it was also my first mix option, so what did I know?

Option #2
*1/2 tsp yeast
*2 cups sugar

Increased yeast and no baking soda. This mix actually worked better with my tap water. This mix would last 2-3 weeks.

Option #3
*1 tsp yeast
*2 cups sugar

This option worked better for me during the winter months and would last up to 4 weeks. Overnight my house would cool down to 65F and the gas would come to a standstill, but once the heater warmed the air up, I would give each bottle a good shake and get things moving again.

What I like about this is that the CO2 production pretty much became nil overnight; but the morning shake would get things moving again.

Option #4
*1/2 tsp yeast
*1 cup sugar

I did not have great success with this mix as it would burn out quickly and needed replacing every 7-10 days.

Option #5
*1/2 tsp yeast
*2 cups sugar
*Single shrimp pellet or fish food flake

Now, I thought this was crazy. Why add fish food to the CO2 generator? But, what I found was that the mix would last 3-4 weeks. By adding the fish food the mix appeared to last a week longer!

I haven't quite worked it out yet, but I believe that the ammonia produced by decomposition may be a factor.

~~~~~~~~~~~~~~~~~

Now, I have also been reading about using Knox Gelatin to make a solid sugar/protein block for the yeast to feed off of. Very interesting, but a lot more work. I plan on trying this one day.

~~~~~~~~~~~~~~~~~

And, earlier this month, I read an article about making wine from a can of frozen grape juice. They took a 1 gallon jug and instructed you to pick up a check valve and airline tubing from an aquarium store. And, provided step by step instructions on how to add the airline into the bottle cap, use hot glue to seal and add the check valve to release the CO2 and not allow air back into the jug. And, in a month you would have wine.

This article got me to thinking about how similar it was to our DIY CO2 generators.

Once the weather warms up, I think I might try this. Making wine in my generator and dosing CO2 into my aquarium! How much better can it get?

Oh, I forgot to mention, currently I am using 1/4 tsp yeast, 2 cups sugar and in 4 bottles I also added 1/4 tsp baking soda. These generator bottles are sitting on top of a heating pad that is left on day and night.

This has been the case for a week now. And, so far so good. The CO2 continues to produce overnight and appears to be more steady. Time will tell if the mix wil burn out in another week or not.

The reason I have 4 bottles with baking soda and 4 without is because I wanted to determine, yet again, if baking soda made any difference.

My tap water tests out at:
6.8 pH
0 NH4
0 NO2
0 NO3
2 PPM PO4
4 dGH
10 dKH
 
  • Thread Starter
catsma_97504
Member
It has been 1 week and the non-baking soda bottles have almost stopped CO2 production while the bottles with baking soda are still going, but slowing down.

I forgot to pick up the gelatin when I was at the store to try the gel mix to have something to compare to. So, in the morning, I will be mixing up 1 tsp yeast, 2 cups sugar and 1/4 tsp baking soda to see how long this mix will last.

Changed out #1 set of bottles and added 1 tsp yeast, 2 cups sugar, 1/4 tsp baking soda and 1/4 tsp corn starch. Reading about alcoholic drink manufacturing and the need for a grain starch gave me this idea.

Never tried using corn starch before. See what happens.
 
DDNA
Member
Is there a link to the article for making the wine? I might want to try that.
 
  • Thread Starter
catsma_97504
Member
Do a search for frozen grape juice wine and you'll get many hits. Here's one of the how tos I was looking at the other day......

If you make wine and gas off the CO2 into your aquarium, please share your experience!
 
psalm18.2
Member
Very interesting. Thanks for sharing! I have often wondered which formula works best. I p/u geletin and yeast to try that formula. I'll be eager to see how it works out for you. I still want to try a plant only tank w/ CO2. Keep posting you results!
 
  • Thread Starter
catsma_97504
Member
Please post your results psalm. It is something that I am interested in trying as well.

It has only been a couple of days since I refreshed one set of bottles and added cornstarch, and I cannot believe how much CO2 is being generated, and how steady the output is. I believe I will use the same mix with each set that gets refreshed over the next couple of weeks. I just hope this mix doesn't start strong and suddenly burn out. Time will tell.

The #1 set of bottles are still going strong after a week. Changed the #2 set of bottles and used 1 tsp yeast, 1/4 tsp baking soda, 1/2 tsp corn starch, 2 cups of sugar. Seeing if extra corn starch will keep the yeast going longer or not.

Has anyone considered using a small sponge filter with CO2? I wonder if it could work? I may have to pick one up and try it.

FYI - the new bottles I set up this afternoon are already producing 1+ bubbles per second. It sure didn't take it long to start producing. As my doors were open most of the afternoon and our high was in the mid 50s, I think the corn starch is helping to get it started faster....and in lower temps.
 
RuanMaritz
Member
is this mixes for 1 liter bottles?
 
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catsma_97504
Member
For a 2-liter bottle. If you are using 1-liter, then cut in half.
 
RuanMaritz
Member
hI so I got my CO2 bottles ready , which mix should I use ? thanks
 
psalm18.2
Member
Did you ever try the mix w/ geletin? Do you think CO2 w/out a tank cover would benefit plants or not? Thanks. Seems the cornstarch & baking soda really help. Good to know.
 
  • Thread Starter
catsma_97504
Member
No, I have not yet tried the gelitin. Too much going on at work.

For now, I've been sticking with the corn starch and baking soda. The mix starts faster and seems to last 2 - 3 weeks.

I still plan on trying the gelitin. Will post results as soon as I do.
 
RuanMaritz
Member
hI catsma should I try the mix#3 you said that it came to a standstill when it cooled down , so what if I put it in a cooler box with a cold pack at night so it will bring the temperature down a bit then it will come to a standstill right? and in the morning I take it out of the cooler box and give it a shake to get it going. , and the plants don't need it at night right ?
 
  • Thread Starter
catsma_97504
Member
It has been my experience that an airstone at night was sufficient. Attempts to force a slow down might make it harder to warm up the yeast mix to get production back in full swing.

If you decide to try this, please post your results. One concern would be too great a fluctuation of CO2, which can lead to a lack of plant growth and an over abundance of algae.
 
RuanMaritz
Member
oh id rather not try that then can't I just take the pipe out of the tank at night ? and what should I put at the end of the pipe an arirstone?
 
Mike_Syr
Member
I am just starting to use CO2 so I am interested in your results.
 
  • Thread Starter
catsma_97504
Member
maritzruan said:
oh id rather not try that then can't I just take the pipe out of the tank at night ? and what should I put at the end of the pipe an arirstone?
I am using an airstone to add CO2 to my tank. I have also tried placing the end of the CO2 line in the intake tube to my filter to help diffuse it better. But, I kept forgetting to check on it and my CO2 production would completely stop before I would notice. This lead to a horrible algae outbreak. So, now it's an airstone. I have also read that you can shove a small piece of chopstick into the tubing to diffuse the CO2, but that it would need replacing every week or two to avoid plugging up.

Mike_Syr said:
I am just starting to use CO2 so I am interested in your results.
Please share your experiences. I started this thread because I was trying out all the various recipes I found on the internet. And, not knowing which worked better or which lasted longer, I wanted to share my experiences.
 
Mike_Syr
Member
I bought a Natural Plant System by Hagen. I made my first batch last weekend. I am getting 6 bubbles per minute on the plastic ladder that came with it. The container is smaller than a 2 liter. I make get more on my next batch. I may also make a larger container to use too.
 
RuanMaritz
Member
I just used the option #3 with two 2l bottles and I'm getting about a bubble a second maybe a bubble and a half a second. I set I up yesterday night , do you think the bubble count will go up?
 
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catsma_97504
Member
It might, but probably not more than 2 bubbles per second. This should be fine for your tank. Just watch it for a couple of days to know.

Since you started both bottles at the same time, you are going to have a sudden drop in production. Once the CO2 production starts to slow down, you will want to start a new mix in one of the bottles so they are staggered to keep production as steady as possible.
 
RuanMaritz
Member
oh ok thanks how long should this last?
 
  • Thread Starter
catsma_97504
Member
I would guess around 4-5 days as this mix is usually done around 7-10 days.
 
RuanMaritz
Member
wow that's not long at all , but it says for you it lasted around 3-4 weeks?
 
  • Thread Starter
catsma_97504
Member
Oops. I've tried so many different mixes, that I am losing track of what they did. You are correct in that this mix lasted about 3 weeks. So, that would mean that you would want to change one bottle in 10-14 days. Then, one bottle every 3 weeks from there. You never want to let the mix completely stop production.
 
RuanMaritz
Member
oh thanks so much . I can't wait for my plants to grow
 
Mike_Syr
Member
This morning I was getting 10 bubbles per minute. This weekend I will work on making a second bottle to use. I think the current mix will last a few weeks. I will also be considering more plants.
 
Mike_Syr
Member
I was thinking of finding a gallon container. I think a restaurant size plastic jar for mayo or salad dressings would be good. Has anyone ever tried a container that size.
 
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catsma_97504
Member
I have not, but other use large, even 5 gallon containers, for Co2.
 
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catsma_97504
Member
Now that all my CO2 generator bottles are holding the mix with the corn starch, I am finding that I am getting 2-3 bubbles per second and am having to watch my tank closely as I am on the verge of overdosing my tank. Plants are loving it....fish are not impressed.
 
Mike_Syr
Member
I got a one gallon plastic jug from a local restaurant. I hope to get the tubing and install it this weekend.
 
Mike_Syr
Member
I am going to hook up the 2 co2 containers to a gang air line valve and feed it to the plastic ladder.
 
  • Thread Starter
catsma_97504
Member
Good luck Mike. Hope it works out for you.
 
Mike_Syr
Member
I put 2 tsp yeast, 4 cups sugar, 1/2 tsp baking soda and 1/2 tsp corn starch in my gallon container. I had problems getting bubbles. I thought it was leaks at the container, but traced it to my gang valve. I paid extra for a metal one that I thought would be better. I switched to a plastic one. It's solid plastic with needle valves and rubber gaskets.

I do have problems with the bubbles coming in spurts and not a continuous stream of bubbles. Does anyone have any ideas why they are not a steady stream?

Now I have to figure out when my little bottle with be done. I will either get another gallon jug or use the little one while I refill the big one.
 
  • Thread Starter
catsma_97504
Member
For me, I usually get 2 bubbles per second; and occasionally 3....and rarely 4-5 bubbles. Does this sound similar to what you're getting?

From what I understand, it all depends on how much CO2 the yeast is creating as well as how quickly it is released from the water in the jug.

It will be interesting to see how long your mix lasts.

Hope this helps.
 
Mike_Syr
Member
I get a big surge of bubbles. So many that some come out of the ladder. Then I don't get any for a second or 2. Then I get a steady stream of bubbles for several seconds until the next surge of bubbles.

I am working 2 jobs now so I don't get much time to watch. I have the next 2days off from one of the jobs. I have other things to do, but I hope to get some time to spend on my tanks.
 
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catsma_97504
Member
It may be entirely possible this is "normal" as you are using a much larger jug than I am. Also, it can take up to 2 days to reach full CO2 production. I'd imagine that once the pressure is built up in the bottle that things would become a bit more steady.

Just keep an eye on it to see if it changes.

Do you have a drop checker or other means to estimate how much CO2 is dissolved in your tank?
 
Mike_Syr
Member
No, I don't have anything to measure the CO2. I just started lloking at methods to measure it.
 
  • Thread Starter
catsma_97504
Member
Here's one method that only requires a few pH tests.....

Remove a couple cups of tank water to a container and aerate it. Test 24 hours later as all CO2 should have been released by this point. We'll call the your tank's natural pH.

While aerating your water sample, test the pH just before lights on, at the half way point and just after lights out. This will give you the pH range as more CO2 is absorbed into the tank. Let's call this sample pH.

Then, do a little math as follows:

(Tank's Natural pH - Sample pH) * 30

It takes 30PPM CO2 to lower pH 1 degree. For example, my tank has a Natural pH of 7.0; and my Sample pH drops to 6.2. So the math would be (7.0 - 6.2) * 30 = 24PPM CO2.

This is only a rough estimate, but will at least give you an idea how much CO2 is getting into your tank.
 
Akari_32
Member
I have a few questions:

Which one of these methods did you find to be easier on the budget, easier to manage, and last the longest (all *relatively* at the same time )?

And do you recommend an air stone, just plain open tubing, or something else?

Last one! How do you reduce the number of bubbles that comes out? Just by tying the tubing, like when you are drip acclimating?
 
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catsma_97504
Member
The best diffuser is actually a small piece cut from a cotton makeup pad. Stuff it into the end of the CO2 tubing. The tighter the better. It will create very fine bubbles to improve diffusion. I use the cotton on my O2 tubes as well, just don't pack it so tightly or it puts too much pressure on the air pump.

Do not attempt to stop the CO2 output from a DIY generator. Otherwise, the bottle will explode. This is why it is important to add an O2 light during lights out.

Hope that helps.
 
Akari_32
Member
I still don't get how to slow the amount of bubbles that comes out.

Also, could I just use, like, a cotton ball, to the same effect?
 
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catsma_97504
Member
Cotton balls are more fibrous and can be difficult to stuff into the tubing. Use less yeast to have a slower output.

You are in Florida, so I'd start with 1/4 tsp yeast and 1 cup of sugar. Others in Florida used half the amount I used. I think it is the difference in weather. Warmer climates use less yeast.
 
Akari_32
Member
catsma_97504 said:
Cotton balls are more fibrous and can be difficult to stuff into the tubing. Use less yeast to have a slower output.

You are in Florida, so I'd start with 1/4 tsp yeast and 1 cup of sugar. Others in Florida used half the amount I used. I think it is the difference in weather. Warmer climates use less yeast.
My dorm is cold. I think my room mate keeps it on 65* @.@ Lately, its been on like, 75, buy yeah. Any recommendations on mixes?

Ok, so make-up pads and t-valves are on my list of things to get
 
HOWsMom
Member
Did you ever try the gelatin ?
 
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catsma_97504
Member
Unfortunately, I never got the chance. There were a few members who said they'd give it a try, but don't know what happened.

If you decide to try gelatin, please share your recipe and experience!

I am always looking for new options to improve DIY CO2. Just this past week, I was reading a thread in another forum where they were experimenting with using garden soil and raw oats. Basically setting up an aerobic composting generator using an air pump. It looks to have a very promising outcome!
 
Echostatic
Member
I've posted this a couple times, thought I'd post it here too. You know, raising awareness and whatnot. Those looking to do DIY CO2 might consider spending a little bit more to get an enjoyable byproduct from the reaction.

You're essentially home brewing already, but the stuff is nasty. This stuff smells amazing when fermenting, tastes pretty good after a couple months, really good after six, and amazing after a year. Oh yeah, and the CO2 will feed your plants just the same So think about swapping a bottle of this into your bottle rotation. It's pretty darned easy. (If anyone wants to give it a go, don't hesitate to PM me with any questions if you don't feel like signing up on that forum.)
 
AdoraDora
Member
I read somewhere that adding some molasses to the mix helped as well.
 
Echostatic
Member
Chopping up about 25 raisins per gallon of water helps as well, as it provides the yeast with nutrients.
 
AquaAddict
Member
I'd like to thank you for your information and recipes! I'm currently using "Option 3" in my experiment to start plants in a 5 gallon bucket!

Thanks a lot!
-AA
 
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catsma_97504
Member
Glad that you found this thread helpful! Good luck with your plants.

Hope you enjoy the forum.
 
Siggi
Member
Hi, Dena.
Think I'm going to start CO2 today. I have been cycling a tank for some weeks; its almost finished (=> nitrates<0,8 after 24h of adding ammonia) so I guess its time to begin adding CO2.
The tank is 300 l (80G), half-full during cycling, so I am planning on using a 5 l bottle (1,5 G). Perhaps your recipe no.5 (the one with a food-flake) will be good, doubling the ingredients.

As there are no fish yet in the tank nighttime CO2 isn't a problem. There are only snails, lots of them. And lots of eggs as well - so I'm in for a snail-boom soon. Perhaps CO2 and increased plant growth will help reduce algae (and snails).
I haven't set on the lights on the tank yet - problems with the timers - so the tank is cycling in an attic and getting some afternoon light. I burned most of the plants with excess ammonia when cycling started, but java moss and vals resisted; dwarf sag is beginning to show green from the roots, echinodorus too.
So I think this will be the best time to start up CO2.
You agree?

BTW: Thanks for the US -> S.I. conversion in the orig post.
 
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