# diy co2 troubleshoot please



## feistyfish (Aug 13, 2006)

So I attempted a diy co2, but so far it hasn't really worked. I am using a 2L soda bottle. I have airline connectors epoxied into the caps. 

My line setup is as follows:

coke bottle --> check valve --> input of gas separator with airline tube running into water --> second airline connector is dry and runs to another check valve (that is at the height of the tank) --> sweetwater diffuser stone.

I have soap tested all the bottle caps and epoxied connectors and check valves and could not locate a leak at all. Also, I have capped the soda bottle with the yeast solution and it did develop pressure within a couple hours. Does the sweetwater stone require too much pressure for one 2L soda bottle to push the co2 out? I don't see any bubbles at all. 

My recipe is 
approximately 3/4 hot water dissolving 2 cups of sugar.

then I activate with 3/4 tsp of yeast in lukewarm 100F water with a pinch of sugar and let it sit about 10 minutes. then add it into the soda bottle along with about 3/4 tsp of baking soda. 

Should I add another 2L soda bottle and see if an increase in pressure will do the trick?


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## evercl92 (Aug 14, 2006)

1) try removing the diffuser - see if you get any production then
2) recipe I always used: 
2cups sugar, dissolved in warm water - add to bottle
add 1/4 tsp yeast
add 1/2 tsp baking soda
fill 2L bottle until the neck begins to taper in

Is "input of gas separator with airline tube running into water" a 2nd bottle you are running in between the reactor and your tank?


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## vic46 (Oct 20, 2006)

Th maximum temperature is 110F, above that and the yeast expires. I don't know how warm your must (sugar and water solution) was but your yeast starter process is correct. The "sweetwater stone" may well be your problem. As you have said, the DIY CO2 process may NOT develop sufficient pressure to drive the stone. Take the stone out and route the CO2 into a filter pick up and see what happens. I am also not real clear on the second bottle. Is this simply overflow insurance? If so, consider using a smaller bottle and simply tape to your primary fermenter. Using a 2 litre bottle just takes up CO2! As I understand your set up, you have 2 check valves. One is adequate just before the line goes in the tank. The check valve will only stop the siphon effect, not the accidental injection of the must into the tank. The second bottle hopefully forestalls that problem. A sure fire through the cap method is the bulkhead through walls used by R/C aircraft buffs for their fuel lines. These are metal with washers and nuts on each side of the cap so the leak likelihood is virtually removed. Also, real cheap and made of brass which CO2 will not corrode. I really hate to add this one but, check and make sure the flow direction is correct on the check valve and that the check valve is functioning properly. I have had some difficulties with the cheap plastic check valves and as a result do not use them. Plastic is very susceptible to CO2 corrosion!
Vic


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## feistyfish (Aug 13, 2006)

Thanks all for the suggestions. The check valves indeed are in the right direction cause after it didn't work the first time, I retried blowing through them to make sure it was correct. The second water bottle with water inside is supposed to prevent muck from getting sucked through to the tank under pressure (gas separator). Because the airline runs into the water, it actually siphons and fills the tube with water up to the check valve that is after the main soda bottle. Since I epoxied the connectors in, I'm fairly sure that there are no leaks at the cap.

So if I got this correctly, your recipe fills the water up to the point where the 2L bottle starts to decrease in diameter, so nearly 2/3 of the bottle or maybe slightly more? Does the amount of water added have an effect on how quickly the co2 is produced or how long the yeast lasts?


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## evercl92 (Aug 14, 2006)

feistyfish said:


> So if I got this correctly, your recipe fills the water up to the point where the 2L bottle starts to decrease in diameter, so nearly 2/3 of the bottle or maybe slightly more? Does the amount of water added have an effect on how quickly the co2 is produced or how long the yeast lasts?


Correct. Filling it up that much forced CO2 out of the bottle, and into the tubing / aquarium. I never had an issue with it pulling water from the tank, back into the 2L bottle. That's what the check valve is designed to prevent. I only used a checkvalve right after each 2L bottle (I ran 4 of them, using T-pieces, into a single output into the tank.) This allowed me to take a bottle off of the system (to remix solution) without losing pressure in the entire system.


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## carpguy (Feb 3, 2006)

feistyfish said:


> Because the airline runs into the water, it actually siphons and fills the tube with water up to the check valve that is after the main soda bottle.


I'm not clear on what you mean by this&#8230;

The airline leading from the Main Mix bottle is suck into the mix water?

If that's the case, that's the problem. It should be just through the cap and well above the water.

Some bottles are designed to hold in CO2, some are not. When I first experimented with DIY CO2 I built a bubble counter/gas separator out of a Gatorade bottle. Gatorade bottles are not designed for this. It leaked. Look for something that keeps carbonated beverages carbonated. Don't discard the gasket if you can help it. Maybe an o-ring would help.

I'd go to a single check valve: it's just another spot for a leak and one before the tank should be all that's needed.


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## feistyfish (Aug 13, 2006)

sorry, i must be just confused with the setup. from what i understood the gas separator has water in it so that it functions as a separator as well as a bubble counter. because the airline is in the water for some reason it seems to siphon it backwards up the airline (in the opposite direction of the co2) up to where the check valve is. This is the reason why i put a check valve there also because before it would even siphon the water from the separator bottle into the main 2L soda bottle. the hole in the 2L soda bottle is free-air without water.

The 2L is a coke soda bottle, but the gas separator bottle is a regular water bottle. I'm not sure if this made a difference because I soap tested the caps and it didnt seem to leak at all.

I'm gonna try to remove the gas separator and see if that makes a difference. Otherwise I'll add another 2L bottle.


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## carpguy (Feb 3, 2006)

If you're getting good production the pressure is outward bound… I'm not sure why you'd be getting a siphon back into the mix bottle. 

My little Gatorade bottle passed the soap test. It failed the fully-submerged-in-the-waterchange-bucket test. At least it did for about half a tube of silicone.

Your starter culture method sounds good, although I'd go a tad warmer (say 105-107). You should get quick results. If you don't smell bread and have a layer of bubbles on top in 20 or 30 minutes you probably don't have live yeast. One of the main functions of starter cultures is testing the yeast before you commit to the full mix, (plus its good for the yeast). 

Try taking the output line from the mix bottle and put it straight into a glass of water. You should get bubbles. That should at least help you settle if its output or a leak.


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## feistyfish (Aug 13, 2006)

thats what i thought as well. i expected at least some co2 production to push through the lines and prevent a siphon from ever forming. 

so i undid the sweetwater diffuser stone and left the airline just hang in the tank. i also removed the gas separator bottle and have the lines directly connected from the 2L soda bottle to the tank. still no bubbles.

so i understand that the water temp is important when reactivating the dry yeast, but is the sugar water that it is added to also important? i just dont quite get what is going wrong. this was supposed to be easy, but now troubleshooting it seems like this just isnt working for me.


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## carpguy (Feb 3, 2006)

feistyfish said:


> this was supposed to be easy&#8230;


Pressurized is easy, DIY is cheap (as least as far as startup costs). DIY _is_ troubleshooting.

Active yeast are active: if you're staring at a bottle of water wondering if anything is happening, nothing is happening. With the starter culture you should be able to see activity in a few tens of minutes.

Yeast is heat sensitive and some yeast is DOA. Hot trucks, hot warehouses, years on a shelf. Its not easy being a yeast. If you never had production, and it doesn't sound like you did, you may just have gotten bad (dead) yeast. Try getting some yeast somewhere else: the same store has the same yeast from the same truck and the same warehouse. Try the next place. A busier place.

Better than the supermarket, if you have any winemaking or homebrew shops nearby, they'll tend to have fresher yeast and useful information. Champagne yeast will tolerate somewhat higher alcohol than the regular wine/bread species, so thats not a bad thing if you come across it (its a few percent difference, nothing earthshaking).

Winemakers have spent centuries puzzling this topic. And they have websites. They've got good info on the care and feeding of yeast.


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## feistyfish (Aug 13, 2006)

thanks for the encouragement. i think thatll probably be my best bet to find some new yeast. and ill try all over again.


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## kiwik (Apr 3, 2007)

i had no other bottles so i did this with a 3.78 liter bottle. would this work? i filled it to about 2/5 full with water that was about 96-98 degrees f.


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