# DIY CO2 mixture



## imrandy85 (Jun 17, 2008)

I've just started to experiment with some DIY CO2 on my 38 gallon planted tank. When I made up the mixture the recipe I was looking at called for 2 cups of sugar and 2 cups of water to go into a 2 liter bottle and 1/4 tsp of yeast to be mixed separately in a small amount of warm water. I let the yeast sit for about 5 minutes before adding it into the 2 liter. After about a day now I don't have any bubbles coming out. I read a lot of posts around the forum here and it seems like most people use more water in their mixture and was wondering if maybe the higher concentration of sugar in my solution could have slowed or maybe even killed the yeast. I filled the 2 liter 2 about 2/3 full of water now but I'm wondering if this will even do any good or if I should dump it all and start over. I do realize that my problem could simply be a leak of some sort, I drilled the holes in my cap smaller than the air hose and pulled it through with pliers, but I wanted to see if something was wrong with my mixture first.

Thanks, 
Randy


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## lovingHDTV (Oct 15, 2008)

I started my first DIY CO2 last night using this recipe and it is going like gang busters. It never says how much yeast to start with so I started with 1/4 teaspoon.

http://www.plantedtank.net/forums/diy/77659-grape-jelly-diy-co2-experiment-3.html


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## wakesk8r (Nov 26, 2007)

I used diy for a while before going to pressurized.
My mix was 2 cups sugar 1/4 tsp yeast fill bottle to where it starts to get smaller.
The trick is to activate the yeast first.
Put it in a shot glass with some warm water then add a little bit of sugar.Stir it like crazy and wait 10 minutes. If it has not doubled in size your yeast may be bad.
to check it for leaks just put some soapy water around all seams and see if it bubbles.
Diy is a cheap alternative but it has it's set backs as well.


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## imrandy85 (Jun 17, 2008)

I think where I slipped up is that I didn't activate it properly first. I set it in warm water for a while but it didn't look like anything happened before I added it to the mix. I'll try and redo my mixture tomorrow and wait until the yeast does something first.


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## imrandy85 (Jun 17, 2008)

I dumped my bottle as it was doing nothing and tried the whole thing over again using the same yeast. I left the yeast in a cup of warm water with a little bit of sugar for probably 15 minutes and nothing happened. I decided to throw everything into the 2 liter and set it up under the tank anyways and still got no results. I'm pretty sure there is no leak anywhere because I accidentally squeezed the bottle and it started to siphon out water from my tank. Do I just have bad yeast or am I doing something wrong? I'm using Fleischman's dry active yeast.


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## RLee (Sep 21, 2008)

you answered your own question, you have bad yeast. Everything you did is fine and should of worked. Buy some fresh yeast and you will be fine.


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## imeridian (Jan 19, 2007)

If your yeast hasn't "foamed" within fifteen minutes of starting the proof, you can definitely consider it to be bad.


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## cjp999 (Nov 18, 2008)

Note that "warm" in this case actually means 100 to 110 degrees. It should actually feel hot. If you use water that feels what most people typically think of as warm, the yeast probably will not activate.


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## imeridian (Jan 19, 2007)

Indeed. Whenever I use yeast I grab my trusty instant read thermometer. 

While one doesn't use this much yeast for DIY CO2, here are the proofing instructions from Red Star:


Red Star Yeast said:


> Using a one-cup sized liquid measuring cup, measure 1/2 cup warm (100 º to 115º) water. Add 1 teaspoon granulated sugar, stir to dissolve. Sprinkle 2 1/4 teaspoons, or 1 packet yeast, slowly over the surface. Stir the mixture; set a timer for 10 minutes; let rest. In 3 to 4 minutes, the yeast will have absorbed enough liquid to activate and will start rising to the surface. At the end of 10 minutes, active yeast will multiply and create a rounded crown of foam to the 1-cup mark.


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## imrandy85 (Jun 17, 2008)

even if my water wasn't quite 100 degrees wouldn't it have done something within the 15 minutes that I let it sit?

is this brand of yeast known to have problems? I've had this package for a while but the expiration date on it is sometime in 2010.


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## imeridian (Jan 19, 2007)

As long as it was close to the right temperature _something_ should have happened.


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## imrandy85 (Jun 17, 2008)

Perhaps I'll stop by the big liquor store in town and pick up some brewer's yeast tomorrow and give that a try then.

Thanks for the help


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## parkman7 (Dec 28, 2008)

Bread yeast works fine for me. I have used different brands no problems. No need to ever check the temperature of the hot water, bread yeast can survive in near boiling temperatures. Just heat the water in the microwave, until it is hot. If it is boiling pour it into another cup to cool it a few degrees then add the yeast. 
Any amount of yeast will work, more yeast will make it fizz faster, while less will take longer but still work.
Check your seals in the bottle to the tubing perhaps you have a leak. Good mixtures should not foam, but make small soda like bubbles. Which may be why you did not notice.
You should start to see bubbles in your tank after 24 hours, swirl the bottle to make the yeast more active.
Even "bad yeast" will have some living, so just double the dosage and use it anyway.
I fill the water up to 9cm (3.5") to the top of the bottle to prevent the yeast from flowing into the tank. Keep the bottle above the tank or at the same level if you do not have a check valve.
Also make sure the sugar is rinsed from the sides of the bottle near the opening, to keep the yeast from climbing the sides.
I believe bread yeast also last longer than brewers yeast, and it's defiantly cheaper


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## Kostyan (Jan 23, 2009)

*My mixture*

I use mixture 2 hubcaps of fertilizers for plants, - 10 soupspoons of sugar, fifth part of tea-spoon of dry yeasts - all on 2 litres. Does not add a soda. Gurgles long, in the beginning very decently, then worse.



imrandy85, I think that a problem is in the loss of СО2.


_PS I am sorry for bad English_


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## brinks (Dec 19, 2007)

I have used this formula for some time with good results, 1 1/2 to 2 cups sugar, 1/2 tsp yeast put into a 2 l. bottle 1/2 full with warm water (right out of the tap) shake it up and fill the bottle to where it starts to narrow. I then put a balloon over the top and when I starts to blow up I know it working.


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## cjp999 (Nov 18, 2008)

imrandy85 said:


> even if my water wasn't quite 100 degrees wouldn't it have done something within the 15 minutes that I let it sit?


I'm not sure. I would suggest just running your hottest tap water into a cup, let it sit a few seconds, and then mix in the yeast.


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## imrandy85 (Jun 17, 2008)

imrandy85 said:


> I'm pretty sure there is no leak anywhere because I accidentally squeezed the bottle and it started to siphon out water from my tank.


I left a mixture of a small amount of water, about a tsp of sugar and a 1/4 tsp out overnight and I didn't see any bubbles. This yeast was from a different packet but the same set of 3. I got some champagne yeast that I'm going to try and see if I get different results.


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## imrandy85 (Jun 17, 2008)

I picked up some Red Star chapmagne yeast the other day and this stuff actually seemed to do something when I activated it. I then proceeded to setup the whole mixture in the bottle. 

Here's my procedure:
1) fill the 2 liter about 1/3 with water
2) add 2 cups of sugar, 1/2 cup at a time, shaking well after each scoop
3) fill the bottle up to the neck with water
4) poor in the activated yeast mixture ( small amount of warm/hot water, some sugar and 1/4 tsp yeast

Now, after about a day and a half I'm still seeing no bubbles from this mixture. I do have a gas separator setup and there are no bubbles there or in the tank. Therefore, I think the next step has to be checking for leaks. The most likely place for this leak has to be the hole around the tubing coming out of the yeast mixture since I'm not seeing anything in the gas separator. Anyone see anything wrong that I'm doing?

Another thought I had was that I have very hard water. Hardness and alkalinity are both at the highest end of my test strips as well as the ones I use at work. My pH looks like its between 8.2 and 8.6. Would having this water chemistry affect the activity of the yeast?


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## cjp999 (Nov 18, 2008)

imrandy85 said:


> I
> Now, after about a day and a half I'm still seeing no bubbles from this mixture. I do have a gas separator setup and there are no bubbles there or in the tank. Therefore, I think the next step has to be checking for leaks. The most likely place for this leak has to be the hole around the tubing coming out of the yeast mixture since I'm not seeing anything in the gas separator. Anyone see anything wrong that I'm doing?
> 
> Another thought I had was that I have very hard water. Hardness and alkalinity are both at the highest end of my test strips as well as the ones I use at work. My pH looks like its between 8.2 and 8.6. Would having this water chemistry affect the activity of the yeast?


Yes, check for leaks. I had the same problem. You can probably just take a dropper of water to get some water around the bottle cap where the tube enters. The water seems to want to stick up against the tub, so this works well, and this is where I found leaks. If the threaded part of the cap is the problem, you'll probably need to find a way to submerse the whole bottle.

To make leak detection simpler, attach the end of the hose to an air pump rather just letting it sit in the aquarium waiting for pressure to build up. This will make leaks much more obvious. You can even do this before you add your yeast mixture. That way you can hold the bottle upside down in a bit of water to check for leaks in the cap.

As for your hard water, I don't believe it is a problem. Mine is hard with a pH around 8.2. That can be an advantage because my understanding is that the pH can drop until it is too low for any fermenting to continue, so starting with a high pH helps prevent or delay this, but you need a high kH also.


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## imrandy85 (Jun 17, 2008)

Thats a great idea with the air pump, I've got a couple extra laying around so I think I'll give that a try. Thanks a lot


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## stonedpuppy (Jan 26, 2009)

i add some crushed up rasberries and let them ferment, then i bottle it and drink it


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## vtkid (Jan 5, 2009)

stonedpuppy said:


> i add some crushed up rasberries and let them ferment, then i bottle it and drink it


You mean you use that as your co2 recipe and then you just get some liquor out of it? if so right on :thumbsup:

I also had a problem with my co2 i used the grape jelly method with bakers yeast and i was getting a lot of bubbles for like 4-5 days and then it just stopped. So i guess there are many ways the diy co2 can go wrong.


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## imrandy85 (Jun 17, 2008)

Well I hooked up an air pump where my CO2 generator should have been and all the bubbles went right through the gas separator and into the tank. That means that my leak was at the lid of my 2 liter bottle. After finding my silicone and super and discovering that both were dried up I pulled the tubing a little farther into the 2 liter bottle. I instantly saw the gas flowing through the tube and bubbles came out into the gas separator, yay.  However, the bubbles coming through are very slow, about 8-10 bpm. Is this because the mixture has been sitting there setup and leaking for a few days or will it speed up after more pressure builds up? There are no bubbles coming into the tank yet but I assume that pressure just needs to build up in the gas separator and the tubing into the tank still.


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## cjp999 (Nov 18, 2008)

I was actually suggesting that you take the tube running into the tank and attach to air pump to it. This will build up pressure in you gas separate and CO2 generator bottle, making leaks obvious. The way you hooked it up, the gas still has an easy outlet into the tank. Basically it is staying pretty low pressure, and it is harder to detect leaks this way. You may have seen an improvement after your fix, but you still may have a small leak.

I'm still new to DIY CO2, so I'm not certain about typical BPM counts. Mine is still running directly into my filter intake, so I can't even see the bubbles. I'll get my CO2 reactor with clear PVC built soon, so I will have a better idea of my bubble count then.

I think I've read that you get 1 bubble every 1 to 3 seconds from 2l DIY CO2, so you are still below this. You could have a slow leak still. It's also possible your mixture it not good.

BTW, I'd suggest trying to get things to work outside of your tank first. Get rid of the gas separator for now. Test just the CO2 bottle for leaks first by hooking the output host to the air pump. Once leaks are fixed, run the output host into a small glass and verify you are getting good bubble counts. Once that is working, add the gas separator, check for leaks again with the air pump, and then check for bubble counts in the glass again. Once all is to your satisfaction, move the setup to your tank.

Note, once you have enough pressure to produce one bubble, then bubble counts should be the same at high and low pressures. For example, you may get bubbles sooner when the hose is 1" deep in the water than when 12" deep because it takes a while for the pressure to build up. However, once you get bubbles, I see no reason why the count would not be the same for both 1" deep and 12" deep unless the higher pressure is causing a leak.


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## imrandy85 (Jun 17, 2008)

Well I went out and bought some silicone and put a bunch of it around the tubes going in and out of the 2 liter bottles and now my diy co2 is working wonderfully. I have a piece of hard airline running down the length of my filter intake and attached to the intake with a rubber band. Then there is about a 2" length of the soft airline again which is curved down underneath the intake tube so the bubbles go right up through the filter. Now I'm wondering if I should setup a second yeast bottle. I have a lot of black beard algae which I'm hoping my new CO2 is going to take care of. As of yet it still looks as healthy as ever, although the 1 bottle has been setup for only about a week. How long does it normally take for the BBA to be effected? Should I setup another bottle? I have 1 x 65 watt 6700K PC bulb, 2 x 21 watt T5 bulbs (1 6700K and 1 colormax). I am autodosing flourish via seachem's recommended dosage and am looking at getting pottasium and phosphorus (dosing separately of course). The plants in the tank right now include crypt wendtii (red and green), crypt lutea, valisneria and 1 anubias plant. I would like to add some kind of nice big sword and maybe some hygro.​


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## cjp999 (Nov 18, 2008)

cjp999 said:


> I
> Note, once you have enough pressure to produce one bubble, then bubble counts should be the same at high and low pressures. For example, you may get bubbles sooner when the hose is 1" deep in the water than when 12" deep because it takes a while for the pressure to build up. However, once you get bubbles, I see no reason why the count would not be the same for both 1" deep and 12" deep unless the higher pressure is causing a leak.


I've had this on the back of my mind since making the posting. Soon afterwards I started to think that the bubble rate would actually go down once under pressure, but not the amount of CO2. The reason is because the pressure squeezes the CO2 into a smaller space. You should notice that bubbles gets bigger as they float to the surface. So in a sense you are getting bigger bubbles at a slower rate.

Today I finally did an experiment and compared bubble counts while under pressure to the rate when not. It went from about 1 bubble ever 3 seconds when not under pressure, to 1 every 9 while under pressure. I know I have no leaks because I did a high pressure leak test.

[EDIT - I should add that my "under pressure" bubble count took place in my Rex reactor, about 2 feet under the bottom of the tank, so this produces more pressure than you would get inside your tank. Also, I had to turn off my canister filter when doing this, because the turbulence in the reactor made it hard to count the bubbles. Clearly the filter is adding even more pressure, since I got a big stream of bubbles when I first turned it off.]


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## coolnick (Oct 28, 2006)

I went to the brewery supply store and got some wine yeast thinking it would work longer since it could handle a higher alchohol content, but it was garbage and would only do 1 bubble every 3 seconds at best. I went back to the grocery store yesterday and got some generic fast rise bread machine yeast in a jar for $2 and mixed up a new batch. Now I am back to 1 bubble per second. I do 1tsp of yeast to 1 cup of sugar in my 2 liters. I have 2 bottles set up and I replenish them on alternating weeks. Week 1 I replenish bottle 1, week 2 I replenish bottle 2, week 3 I replenish bottle 1, and so on. This makes things a lot more consistent.

With your large tank you definitely want 2 if not more bottles. I have 2 bottles alternating bi-weekly on a 10g. I am setting up a 20L right now and I think I will have 4 bottles, alternating 2 bottles bi-weekly. It will basically be double what I am doing right now.

Get a drop checker and keep adding CO2 until you see green. I got mine here.


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## cjp999 (Nov 18, 2008)

*Only* 1 bubble every 3 seconds? I finally just got there today after my 5th attempt. I never did better than a bubble every 15 seconds before then, and I'm sure I had no leaks.

I used Fleishmans (sp) yeast. Started with 1/4 teaspoon (yes I activated it), eventually started adding more on following days when I was seeing very little production, but that didn't help. Finally yesterday I started my 5th with about 2 tablespoons (not teaspoons) of yeast and today I'm seeing a bubble every 3 seconds.

One question I have is how much the initial amount of yeast matters. I would think the yeast would quickly multiply until they reach a number they can't really grow past for some reason (lack of space, or lack nutrients other than sugar maybe). That would mean the amount of yeast you put in would only affect how quickly you got to max CO2 production levels. However, that has not been my experience so far.


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## illjay (Jan 22, 2009)

hey randy so the Fleishmans active dry yeast doesnt work? i just bought some and tried it out 4-5 hours ago for the first time and....nothingggg


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## cjp999 (Nov 18, 2008)

illjay said:


> hey randy so the Fleishmans active dry yeast doesnt work? i just bought some and tried it out 4-5 hours ago for the first time and....nothingggg


I seriously doubt it doesn't work given that pretty much every set of DIY CO2 instructions I've read tell you to use it. Did you activate it in hot water? Are you sure you don't have leaks? Did you sterilize?


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## coolnick (Oct 28, 2006)

Yes the amount of yeast that you start with matters. Lower amounts means lower bubble output but longer life and vice versa with the higher amount of yeast. I would also pay more attention to the temp of the water than just "hot". I use an instant thermometer and set it to around 102*F, which is barely warm to the touch. They include specific temps on the package for a reason. If so and so is doing it in 300* water (lol) with great results that is fine and dandy for them, but if you are having trouble you might want to pay more attention to the little details.

1 bubble every 3 seconds and my drop checker was bright blue on my 10g. 1 bubble per second and it is finally green. Ditch those little packets and buy a jar of the quick rise yeast. I bought the generic stuff and it is working great. After you open the jar be sure to toss it in the fridge.


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## cjp999 (Nov 18, 2008)

coolnick said:


> Yes the amount of yeast that you start with matters. Lower amounts means lower bubble output but longer life and vice versa with the higher amount of yeast.


Why? Does the amount of yeast put in limit the maximum size of the colony? Ie, more yeast means the colony can grow larger. If no, then wouldn't you see increasing CO2 until some other limit was reached, meaning no matter how much yeast you put in, eventually the CO2 production would stabilize at the same rate? If yes, I'd like to understand why.



coolnick said:


> I would also pay more attention to the temp of the water than just "hot". I use an instant thermometer and set it to around 102*F, which is barely warm to the touch. They include specific temps on the package for a reason. If so and so is doing it in 300* water (lol) with great results that is fine and dandy for them, but if you are having trouble you might want to pay more attention to the little details.


Actually I find 102 to feel pretty hot. I have checked with a thermometer to make sure it is between 102 and 110.



coolnick said:


> 1 bubble every 3 seconds and my drop checker was bright blue on my 10g. 1 bubble per second and it is finally green. Ditch those little packets and buy a jar of the quick rise yeast. I bought the generic stuff and it is working great. After you open the jar be sure to toss it in the fridge.


 I don't think I'll ever be at the point of needing to bother with a drop checker in my 46g. I have one bottle now. I'll add a 2nd this weekend.

I'll look for a jar of generic yeast.


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## coolnick (Oct 28, 2006)

cjp999 said:


> Why? Does the amount of yeast put in limit the maximum size of the colony? Ie, more yeast means the colony can grow larger. If no, then wouldn't you see increasing CO2 until some other limit was reached, meaning no matter how much yeast you put in, eventually the CO2 production would stabilize at the same rate? If yes, I'd like to understand why.
> 
> 
> Actually I find 102 to feel pretty hot. I have checked with a thermometer to make sure it is between 102 and 110.
> ...


I was under the assumption that the amount you start with was the limiting factor, I could be wrong since I haven't bothered to experiment.

Man 105 barely feels warm to me, I do the dishes at a much higher temp lol.

Yeah I didn't think I needed a drop cheker either, but my problems with the wine yeast were really confusing since I was blinded to the fact that the yeast could be the problem. Generally you can go by the health of the plants, but when problems arise, and they will, it is nice to have that visual cue from the drop checker.

Here is my setup:


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## cjp999 (Nov 18, 2008)

coolnick said:


> I was under the assumption that the amount you start with was the limiting factor, I could be wrong since I haven't bothered to experiment.
> 
> Man 105 barely feels warm to me, I do the dishes at a much higher temp lol.


It takes me forever to get into a 102 degree hot tub!


coolnick said:


> Yeah I didn't think I needed a drop cheker either, but my problems with the wine yeast were really confusing since I was blinded to the fact that the yeast could be the problem. Generally you can go by the health of the plants, but when problems arise, and they will, it is nice to have that visual cue from the drop checker.
> 
> Here is my setup:


Do I see water in your small bottle? I thought part of it's purpose was to capture the yeast mixture shooting out of your CO2 bottle and into the tank. With so little air in the small bottle, even a small accident will result in the yeast mixture getting in your tank.

I also see you fill your CO2 bottles a lot more than I do. Still 2 cups of sugar, right? Does filling it up with more water seem to help? At the very least, it should pressurize quicker.

I never could get a good seal just running the airline tubing directly into to cap. Caulk didn't help. I tried various size holes (tight to loose). I've tried clear, blue, and green tubing. I have not tried CO2 tubing. I'm not sure if that helps with the seal or not.

I tried the Foremost bulkhead fittings I've seen recommended, but they leak from the barb fitting like crazy when using a 3/16" airline. What I have now is the is 1/8" airline hosing connected to the Foremost bulkhead fitting, and then I just force the 1/8" airline hose onto a 3/16" connector barb to convert to a 3/16" hose. Problem is that the 1/8" hosing is so rigid that it will also lose the seal at the Formost barb if the hose is moved around.

Next thing I plan on trying is just gluing a 3/16" threaded airline fitting from the underside. This should give a nice seal because there is a large flat surface to glue.


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## coolnick (Oct 28, 2006)

cjp999 said:


> It takes me forever to get into a 102 degree hot tub!
> 
> 
> Do I see water in your small bottle? I thought part of it's purpose was to capture the yeast mixture shooting out of your CO2 bottle and into the tank. With so little air in the small bottle, even a small accident will result in the yeast mixture getting in your tank.
> ...


Yeah the water in the small bottle is just an air separator/bubble counter. I haven't had any issues with it. I did drop one of the bottles one time and the little bottle contained the mess.

I only do 1 cup of sugar and it works great. Nearly every recipe I see calls for 1 cup of sugar and anywhere from 1/2-1 tsp of yeast.

I just use cheap airline from petsmart and I drill the hole in the cap about the same size as the ID of the airline. It is a real PITA to pull the line through, but it will come through after a few minutes of messing with it. I have never had any issues with leaks.


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## cjp999 (Nov 18, 2008)

coolnick said:


> Yeah the water in the small bottle is just an air separator/bubble counter. I haven't had any issues with it. I did drop one of the bottles one time and the little bottle contained the mess.


I guess that depends on how much air space you have in the little bottle. A big ejection from one of the big bottles probably won't be contained. The bubble counter is a neat idea however. Maybe you should just add a 4th bottle. 



coolnick said:


> I only do 1 cup of sugar and it works great. Nearly every recipe I see calls for 1 cup of sugar and anywhere from 1/2-1 tsp of yeast.
> 
> I just use cheap airline from petsmart and I drill the hole in the cap about the same size as the ID of the airline. It is a real PITA to pull the line through, but it will come through after a few minutes of messing with it. I have never had any issues with leaks.


Yep, and it seems many have success with this approach. I haven't for some reason. Could be that my line is under a lot more pressure than yours. Mine attaches to a CO2 reactor about 42" below the top of the tank. Besides all the added water pressure, there is also pressure from the filter (as made evident by the big release of CO2 when I turn the filter off).


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## coolnick (Oct 28, 2006)

cjp999 said:


> I guess that depends on how much air space you have in the little bottle. A big ejection from one of the big bottles probably won't be contained. The bubble counter is a neat idea however. Maybe you should just add a 4th bottle.
> 
> 
> Yep, and it seems many have success with this approach. I haven't for some reason. Could be that my line is under a lot more pressure than yours. Mine attaches to a CO2 reactor about 42" below the top of the tank. Besides all the added water pressure, there is also pressure from the filter (as made evident by the big release of CO2 when I turn the filter off).


What type of reactor are you using? I have never put a pressure gauge on my CO2 bottles, but I would guess it would read somewhere in the neighborhood of not much. If you are trying to fight the pressure of another device that is probably something you are not going to win. In that event you should consider another method of diffusion. You can also rest your bottles on top of your tank for a day to see if that helps at all, though it should make absolutely no difference since air doesn't weigh much.


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## cjp999 (Nov 18, 2008)

coolnick said:


> What type of reactor are you using? I have never put a pressure gauge on my CO2 bottles, but I would guess it would read somewhere in the neighborhood of not much. If you are trying to fight the pressure of another device that is probably something you are not going to win. In that event you should consider another method of diffusion. You can also rest your bottles on top of your tank for a day to see if that helps at all, though it should make absolutely no difference since air doesn't weigh much.


I think it is usually referred to as a Rex reactor. I know others have used if for DIY CO2, and it is usually placed below the tank.

You are right that raising the bottles would not help. That only moves the weight of the air up, not the 42" of water that is creating pretty much all the pressure. Moving the whole reactor up higher would work, but that's not really practical given the space I have around my tank.

Note I have gotten it to not leak, I just don't believe the setup will remain leak free for long. I first tested it with an air pump and a bucket of water. It seem to work great. Then the air line got knocked around near the bottle cap, and it started to leak. I had to cut the tip of the air line off and reconnect to get a tight seal again.


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## coolnick (Oct 28, 2006)

cjp999 said:


> I think it is usually referred to as a Rex reactor. I know others have used if for DIY CO2, and it is usually placed below the tank.
> 
> You are right that raising the bottles would not help. That only moves the weight of the air up, not the 42" of water that is creating pretty much all the pressure. Moving the whole reactor up higher would work, but that's not really practical given the space I have around my tank.
> 
> Note I have gotten it to not leak, I just don't believe the setup will remain leak free for long. I first tested it with an air pump and a bucket of water. It seem to work great. Then the air line got knocked around near the bottle cap, and it started to leak. I had to cut the tip of the air line off and reconnect to get a tight seal again.


Yeah it seems like it wouldn't work too great with a Rex reactor. If I were you I would try a powerhead or something. That is how I plan to diffuse in my 20L.


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## imrandy85 (Jun 17, 2008)

I couldn't get my Fleischman's yeast to work but that doesn't mean that as a brand it won't work. I had mine sitting in a drawer for months before I used it, so I have a feeling that may have had something to do with it even though it was within the expiration date. I activated my Fleischman's and my red star champagne yeast and nothing really happened with the Fleischman's. Yes, I did have leaks and couldn't get the red star to bubble into the tank until I sealed up all my holes with silicone.


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## B16CRXT (Feb 7, 2009)

I put 3 cups HOT tap water in a cranberry juice bottle with 2 cups of sugar. Shake until sugar is dissolved. Then I add 1/2 teaspoon dry yeast and another cup of hot water and shake it like crazy. Get co2 within an hour.


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## smackpixi (Feb 14, 2009)

some fun discussion and experiences here. i've been doing diy bottles for about 5 months now. 4 bottle system on a 55 gal. 

one thing i can offer to the discussion because i have some baking background is that you do NOT want to use HOT water when starting your yeast. 100 degrees is good. this will feel either warm or lukewarm to your hand or finger depending on your interpretations of the words. will not feel hot. "hot" water will certainly activate your yeast...but it will also shortly kill most of it and ruin your bread...er co2 system


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## B16CRXT (Feb 7, 2009)

good tip. Mine is producing the crap out of some co2 still. Made it about a week ago with hot water. I'll try using warm next time and see if it lasts even longer.


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## cjp999 (Nov 18, 2008)

Chris. said:


> good tip. Mine is producing the crap out of some co2 still. Made it about a week ago with hot water. I'll try using warm next time and see if it lasts even longer.


I think if you have good production, then you did a good job activating the yeast. If you improve your activation even more, your batch would actually last for a shorter period of time, but with more production.


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## cjp999 (Nov 18, 2008)

Ok, I think I've finally figured out my yeast CO2 production problems. My first 4 batches never did better than 1 bubble every 10 seconds. I was always sure to activate the yeast first in a 1/4 cup of 100-110 degree water + sugar, and it always foamed up nicely. I used between 1/4 and 1 tsp of yeast each time.

My 5th bottle, out of frustration, I dumped in about 1 *tablespoon* (maybe even two) of yeast. This got me 1 bubble every two seconds by the next day, but by the 2nd or 3rd day it was back down to 1 bubble every 10 seconds, and is still there a week later. Since it is back to the rate I normally get, I don't think it fizzled out. I think the yeast just weren't capable of surviving in such high numbers for very long.

So, I made two changes. The first was to use bottled water instead of our well water. Our well water is hard, but goes through a softener, so it ends up with a lot of sodium, and still has a high kH. The other change was to to fill the 2l bottle about 80% full, rather than the less than 1/2 full I was getting with just the 2 cups of water I saw recommended. I tried just 1/4 teaspoon of yeast, and was getting 1 bubble every 2 to 3 seconds the next day. I repeated this with a second batch I started the next day.

I'm not sure if it was changing to bottled water or the extra water that helped, but I'm sticking with both.


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## imrandy85 (Jun 17, 2008)

Thats interesting about the bottled water, I'm also on a well where my water is very hard. I fill my bottles up to where the diameter starts to get smaller towards the cap. With one bottle hooked up I got about 1 bubble per 8 seconds. Now that I have two bottles I'm getting about 1 bubble per 5 seconds. I was already wondering if the hardness and very high pH and alkalinity had any effect on the production of the yeast. Perhaps I'll try to mix up a couple of bottles with distilled or RO water and see what I get.


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## cjp999 (Nov 18, 2008)

imrandy85 said:


> Thats interesting about the bottled water, I'm also on a well where my water is very hard. I fill my bottles up to where the diameter starts to get smaller towards the cap. With one bottle hooked up I got about 1 bubble per 8 seconds. Now that I have two bottles I'm getting about 1 bubble per 5 seconds. I was already wondering if the hardness and very high pH and alkalinity had any effect on the production of the yeast. Perhaps I'll try to mix up a couple of bottles with distilled or RO water and see what I get.


Are you on a softener? My water is, so I actually have 0 GH but still have high KH, and of course extra NA. Maybe I'll try water from the outside spigot, which is what I use in my tanks. It does not go through the softener, so it has a high GH.

As for high pH, I've read some advice to add some baking soda to raise the pH, the thought being that the yeast will eventually quit when the pH takes a dive, which it will do eventually. Adding baking soda should keep the pH at good levels for a longer period. Therefor I would think that using alkaline well water would be a good thing.


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## imrandy85 (Jun 17, 2008)

I'm not on a softener, my gH and kH are both real high.


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## cjp999 (Nov 18, 2008)

imrandy85 said:


> I'm not on a softener, my gH and kH are both real high.


Ok. I'm not so sure about R/O water. Seems like it would quickly go acidic. Maybe half R/O and half well would work.


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## coolnick (Oct 28, 2006)

I have extremely hard water and I have no issues whatsoever. My gh and kh test kits don't come anywhere near the range I would need to get an actual reading. RO water would not be a good idea since the ph would crash instantly. If you have to add baking soda to RO water to keep it stable, then I would just stick with the tap.

cpj999 I think most recipes suggest preparing your yeast culture in 1-2 cups of water, which you add to your 3/4 full 2 liter bottle. I think it was the volume of water that helped, not the bottled water. I would just use your un-softened tap water.


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## cjp999 (Nov 18, 2008)

coolnick said:


> I have extremely hard water and I have no issues whatsoever. My gh and kh test kits don't come anywhere near the range I would need to get an actual reading. RO water would not be a good idea since the ph would crash instantly. If you have to add baking soda to RO water to keep it stable, then I would just stick with the tap.
> 
> cpj999 I think most recipes suggest preparing your yeast culture in 1-2 cups of water, which you add to your 3/4 full 2 liter bottle. I think it was the volume of water that helped, not the bottled water. I would just use your un-softened tap water.


It could also have been the fact that the water was softened. No Ca or Mg, plus a lot of extra Na. I'll give unsoftened water a try next time.


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## dtaubert (Nov 4, 2008)

i have a 16 gallon bow front tank. i just did my first co2 attempt i got the large ragu bottle (2lb 13oz) drilled a hole in the top and put the hose through then sealed the top and bottom with liquid nail clear small project. the ran the hose to a check valve then to a air diffuser put the air diffuser in the in take of a ac mini. my recipe for co2 was 2 cups hot water 1/2 cup suger 1/4 teaspoon quick rise yeast put it all in the bottle shook it up 5 min later im getting 1 bubble every 3 sec


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## redfalconf35 (Feb 24, 2008)

I don't measure out all the ingredients, but i have a generic idea of how much i use. My water is "essence of rock", so the gh and kh are surely ridiculous. I put in maybe 1.5-2 cups of sugar, 1-1.5 tablespoons of baking soda, and maybe 1/4 teaspoon of yeast (i save my yeast culture each time so i don't have to add more every time). Then i fill the bottle up to the beginning of the neck with lukewarm water, give it a good shake, and hook it back up. Within an hour i'm getting 1-2 bps, which holds for the next week until it starts to fade. by 1.5 weeks, it's more like 1 bubble per 2 seconds. It stays at that rate for another week or so before starting to "pitter out".


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## B16CRXT (Feb 7, 2009)

2 weeks later I'm getting 2 bps.:thumbsup:


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## cjp999 (Nov 18, 2008)

cjp999 said:


> Ok, I think I've finally figured out my yeast CO2 production problems. My first 4 batches never did better than 1 bubble every 10 seconds. I was always sure to activate the yeast first in a 1/4 cup of 100-110 degree water + sugar, and it always foamed up nicely. I used between 1/4 and 1 tsp of yeast each time.
> 
> My 5th bottle, out of frustration, I dumped in about 1 *tablespoon* (maybe even two) of yeast. This got me 1 bubble every two seconds by the next day, but by the 2nd or 3rd day it was back down to 1 bubble every 10 seconds, and is still there a week later. Since it is back to the rate I normally get, I don't think it fizzled out. I think the yeast just weren't capable of surviving in such high numbers for very long.
> 
> ...


I gave using well water that has not gone through the softener a try. After sitting overnight it was only doing about 1 bubble every 20 seconds. So the problem is not because softened water has a GH of 0, and is not due to the volume of water added (filling about 80% in both good and bad batches). The only other variable I can think of is KH/pH. It is about 8.2 in both softened and unsoftened water, but closer to 7 when I use bottled water. I read that yeast does not do well with a pH above 8.0.

As more evidence of pH being the problem, I went to replace my 5th bottle mentioned above. It was made with well (tap) water about 2 weeks ago. It started a 1 bubble every 2 because a put a lot of yeast into it, but after 2 or 3 days was at 1 bubble every 10 seconds. Now it's still going at 1 bubble every 4 or 5 seconds. I know the pH drops in yeast bottles, so maybe now it is in a more favorable range.

I'm going to trying adding a bit of muriatic acid to the batch I just made and see if that helps.


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## coolnick (Oct 28, 2006)

My tap water PH is in the low 8s, I doubt PH is your problem. Try a different batch of yeast.


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## cjp999 (Nov 18, 2008)

coolnick said:


> My tap water PH is in the low 8s, I doubt PH is your problem. Try a different batch of yeast.


Maybe it is some combination of things. Possibly your yeast likes the 8s and mine doesn't. I just know that this yeast has only worked well in bottled water, which has a pH around 7. It does not work well in well water with a pH around 8.2, whether it is softened or not, but does seem to get better in the well water over extended periods of time (more than 1 week).


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## cjp999 (Nov 18, 2008)

Been a while, but I thought I would update some of my findings. Originally I had very poor production (about 1 bubble per 10 seconds, lasting for weeks on end). Switching from water that had gone through the softener to water straight out of the well helped quite a bit. Filling the bottle about 80% full instead of 50% also help some.

My more recent finding was the benefits of adding baking soda. I add a few tablespoons, and that seems to make the bottle produce a lot longer. I figured this out when I dumped a bunch of baking soda into a bottle that had slowed production quite a bit after a week. The production went back to "new" rates, and stayed there for about another week.


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## Broaska (Nov 25, 2009)

B16CRXT said:


> I put 3 cups HOT tap water in a cranberry juice bottle with 2 cups of sugar. Shake until sugar is dissolved. Then I add 1/2 teaspoon dry yeast and another cup of hot water and shake it like crazy. Get co2 within an hour.


I tried this and it works great for me! Although I am only using 1 cup of sugar per bottle. I have 2 apple juice bottles connected with a brass t-valve that go into my DIY bubble counter. Lasts a good 3 weeks at a fairly consistent rate. :thumbsup:


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