Just made DIY co2

[MyShrimpDied]

I just made my own DIY co2 and it doesnt look like it's working that well, the water is siphoning back into the bottle. here's the recipe i used.

2 cups sugar
1/4 tsp yeast
pinch baking soda

i added all that stuff, added about a cup of warm water, shook it up to dissolve the sugar and yeast then filled the rest of the bottle about 3 inches from the cap, then shook it up very well.

then i attached the tubeing into the intake of my filter. and now the water from the tank is starting to siphon into the bottle.
What did i do wrong? could you help me out with your DIY co2 experiement experience?

~ MyShrimpDied

 

[TPIRman]

Did you add a check valve in the tubing between the soda bottle and the tank? This will likely solve your troubles. Here's an example of what I'm talking about.

The Tetra ones are generally the best, and they're cheap, so you might as well get a quality one. Your LFS should definitely have these in stock.

Hope that helps.

-John

 

[TonyN]

A check valve is a good idea, but just out of curiosity, how long had you had it going before you posted here? Sometimes it takes 6 or 8 hours to start cooking good. Once it does it will push all that water in the tubing back into the tank with the Co2.
Also, what height, compared to your tank did you put the bottle?
If its too high it can do that. I keep mine on the floor with no check valve and have never had that problem.

 

[Murdock]

How hot was the water you added.?
If it was very warm it will kill the yeast, also how old was the yeast you used?

 

[ChicoRaton]

I'll just kind of repeat what the other people said. a check valve is a necessity. Also, it can take a few hours for co2 production to begin. the yeast take a while to get going.

Also, The water should be about 110 degrees, no hotter. About the temp of a warm bath or a hot tub. use a thermometer if in doubt. this is enough to give the yeast a jump start but not hot enough to kill them. hope that helps

 

[Murdock]

One thing to remember is that adding more sugar than called for will not make things work better.

I make wine all kinds and one thing is that when your specific gravity 'SP' gets too high, too much sugar, the yeast has a very hard time to get started. Also adding more sugar will not make the over all production of CO2 more. The CO2 production stops when the alcohol, the waste from the yeast, reaches lethal levels for the yeast.

You can test your yeast by simply putting some in a bowl with a little sugar. After 15 min there should be tiny little bubbles on top of the water.

80º Water Would Be The Best to start the yeast, then it needs to be 75º Ideally. But once it gets going I'd say 68º-90º the yeast should keep going. The higher the temp in that range the faster the yeast will work to a certain extent.

HTH

Kevin...

 

[Torf]

If you closed the system while the water was warm, the air trapped in the bottle will contract as the bottle cools. This will cause a little bit of suction that may be strong enough to lift a column of water several inches. Plenty to start a siphon.

If you are using a collapsible bottle, squeezing it even a little bit while closing the cap can create low pressure in the lines as well. Until the CO2 production offsets the volume in the plastic, water will be sucked up to offset the pressure.

Capillary action can also pull water up a thin tubing. This action is weak but inevitable. A siphon could result.

In order to reduce the risk of these things try some simple solutions:

Place the generator level with the top of the water.
Install a check valve to limit the flow back into the lines.
Use a ribbed rigid plastic bottle instead of a smooth flexible one.

It may take as long as 12 hours to start CO2 production. All the lines will have to be pressurized enough to push the CO2 down into the water so once it does start to bubble it may still take some time for an equilibrium to be reached and bubbles to start coming out. If there is water in the line, all that will have to be pushed out of the way as well. Don't worry about the pressure getting to be too high. Soda bottles can handle a LOT of pressure before bursting. Just don't leave the system plugged for hours at a time.