Need Help on DIY Co2 generator

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atticus27

Aquarium Advice Apprentice
Joined
Dec 3, 2008
Messages
11
Yesterday I made a co2 generator....I got about a 1 liter bottle, connect that to an empty bottle (so junk can get into the empty bottle and not in the aquarium) and in that empty bottle i connected another tube that goes into the tank. the problem is, since last name at 9pm till now, theres no co2 going into the aquarium. When i shake up the bottle with a cap and open it, it makes a fizz sound but i'm guessing the pressure isn't strong enough to reach into the aquarium..

How do I fix that problem? add more yeast?

also, I don't have an airstone, i just put the tube in the tank and now it's dangling in there.

Please help! thanks!!
 
Atticus, if the system is airtight, you will see CO2 bubbling out of the system (assuming the yeast is active, and not dead.

There are only 2 explanations: You mixture is not viable so it is not producing CO2, or, you have a leak somewhere. If there is no leak, and the system is producing CO2, it only has 1 place to go, and that is out the hose into your tank.

If you are pretty sure your mixture is working (a half cup sugar, 1/4-1/2 tsp of yeast, and an 1/8 tsp of baking soda should do it, activate the yeast outside the bottle before sealing it), then check your hose connections/caps with soapy water and a pastry or paint brush. If it is leaking, you will see the soap making bubbles, even if it is a very small leak.

You can use silicon or superglue to seal up your connections if necessary.
 
Atticus, if the system is airtight, you will see CO2 bubbling out of the system (assuming the yeast is active, and not dead.

There are only 2 explanations: You mixture is not viable so it is not producing CO2, or, you have a leak somewhere. If there is no leak, and the system is producing CO2, it only has 1 place to go, and that is out the hose into your tank.

If you are pretty sure your mixture is working (a half cup sugar, 1/4-1/2 tsp of yeast, and an 1/8 tsp of baking soda should do it, activate the yeast outside the bottle before sealing it), then check your hose connections/caps with soapy water and a pastry or paint brush. If it is leaking, you will see the soap making bubbles, even if it is a very small leak.

You can use silicon or superglue to seal up your connections if necessary.
so 2 cups of sugar in a 2 liter was overkill....
 
I would think 2c is more than enough, but it wouldn't stop the mix from working. If your mix isn't producing any co2, then most likely the yeast was either dead, or not activated prior to putting in the anaerobic environment of your bottle. The best way to get your yeast going to is to put them in a dish with a little warm (not hot) water, a little sugar, and let them sit for 5-10 minutes. It will form a frothy head and smell like bread when it is ready to throw in the bottle.

More than likely though, you have a leak somewhere in the system.
 
Well... I never knew you had to activate the yeast beforehand. I've done it just by putting everything into the 2L and shaking really hard and it has worked well so far for me. Time to re-do one of my 2Ls anyway so maybe I'll try that this time.

Of course that may be why it takes 8-10 hours before mine starts producing CO2.

As to the mixture there are a bunch of different opinions I guess. I'm just going to stick with my first one, which is 1 cup sugar, 1 tsp yeast and 1/2 tsp baking soda.
 
Yeast starter

Yeast don't do as well in a high sugar concentration as they do in a medium one. Also, they don't like bacteria at all. So, sterilize the bottle and cap and the will last longer.

A good starter is what I use for wine and it is no trouble really. Of course you will need to use a simple syrup instead of the grape juice. (Sad really)( I mean, if you guys are going to make booze in a bottle, you should make the good stuff. lol.)

1/2 cup of warm water (about 95- 100'F), too hot and dead yeast, too cold and they don't wake up. Sprinkle the yeast over the water and lit sit for 5 min. Mix 2 cups water and 2 cups sugar in a sauce pan, bring to a boil, stir till all the sugar is dissolved, and set aside and let cool to room temp. This is a simple syrup. ( you can multiply the quantity of this and store it in the fridge in a glass jar (sterilized) practically forever.)
mix 1/4 cup of the simple syrup and 1/4 cup of water (both at room temp) with the yeast and let sit for 10 min. If the yeast was good, you will know. Finally mix 2 cups of the syrup, 1 cup water, and the starter mix in a sterilized 2 or 3 liter bottle, cap and use.

The mix should last until the alcohol content of the mix gets too high for the yeast or till all the sugar is consumed. With that much sugar I would guess it will stop at 5-8% alcohol depending on the yeast used. You could probably get those %'s up with a brewing or wine making yeast, but it's probably not worth the extra cost.

Hmmm.
Wonder if there is a way to hook up the 6 gal. wine carboy? Seems a shame to waste all that co2.
 
I used champagne yeast for awhile in my DIY system - and I concur with Jim -- after tracking the results I concluded the special yeast lasted about 1 day longer on avg than just regular yeast, so not worth the extra cost.
 
i had 2 cold 2L that never did produce anything (2cups sugar, dash of baking soda). yeast was just tossed into them at startup. nothing for a week or so. i then started some yeast separately for 10 minutes, and tossed them into the 'dead' 2L's, and they started bubbling in a matter of minutes.
so yes, activate the yeast.
 
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