# DIY co2 mix questions



## LiLGuppyGal181 (Feb 14, 2006)

I have a 12gal tank, not too heavily planted, and Im making a DIY co2 dispenser out of a large juice bottle. my question is how much yeast/ sugar ratio should I use? I have sugar cubes (that just happens to be what I have). 

thanks,
Laura


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## redFishblueFish (Feb 12, 2006)

The sticky at the top of the DIY forum has a great link on yeast CO2: http://www.qsl.net/w2wdx/aquaria/diyco2.html This site has 2 different mixes along with some great info on the other elements of DIY CO2.


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## LiLGuppyGal181 (Feb 14, 2006)

thanks!


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## LiLGuppyGal181 (Feb 14, 2006)

so I followed all the directions in the sticky to a T (1/4 oz yeast, 2 cups sugar) but for some reason I cant get my mix to yeild anything for more than about 5 hours. it does really well at first, only taking about half an hour to start bubbling, then slows untill nothing else comes out. is there something I should add/ adjust? could it be the sugar cubes? anything Im not thinking of?

thanks
Laura


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## hoppycalif (Apr 7, 2005)

Temperature is also important. Yeast slows way down if it gets too cool. One poster here even made a system with the DIY bottle in a water bath with a heater in it, and the heater connected to a timer to "shut off" the CO2 at night. The object is to keep it just warm - not hot.


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## neonfish3 (Feb 12, 2004)

LiLGuppyGal181,
Did you add 1/4 t. (teaspoon) or 1/4 oz. Big difference, I think the recipe calls for 1/4 t of yeast.
*From the site that was posted earlier:*
For two-liter bottles:

2 cups water
2 cups Sucrose (cane sugar)
¼ teaspoon Fleischmann's Active Dry Yeast
¼ cup tepid (ideally 104ºF) water
*1/4 oz= 1 packet of red star yeast= 2 +3/4 teaspoons of yeast.* 
If this is how much you used then the yeast is using up all the sugar and dieing. ( Thats not quite right, I don't know how to say this correctly). But I bet you had GREAT CO2 production for a while.:eyebrows:

If you used 1/4 t. of yeast and it stopped working that quick then you probably have a leak in your system somewhere.
When I was running DIY CO2 I used to use 1/2 teaspoon yeast, 2 Cups of sugar and slightly warm water filled up the top of the label of what ever bottle I used. (usually 2 liter soda) This mix would start out good and increase for a few days then gradually dwindle down in production till I replaced the mix after 10 days to 2 weeks.


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## Mjproost (Nov 17, 2005)

I agree with neonfish, check for leaks first. I was always battling leaks with DIY CO2. 

Does your juice bottle have a larger cap like say 1-1/2" across. If so that could be your culprit. They don't seal as well as the lids on a 2 liter. You try using some teflon tape on the threads to seal that up. The second most likely place is where the tubing goes into the cap of the bottle. 

Second, do you have really soft water? If so, its possible that the ph is crashing and your yeast is dying. try adding some baking soda to your mix.

Third, IME the DIY generators had a huge burst right away and then leveled back down to their normal ouput. I always made my mixes 24 hrs prior to hooking themn up.

Fourth, did you check the temp of the 104 degree yeast rehydration water? IME, you better off too cool than too warm. How about your mix water? If that is too warm when you put the yeast in could cause some issues also.

Whew, I hope this helps!

BTW- Flourish Excel is excellent carbon source in same tanks


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