Re: CO2 Content in DIY Yeast

["Wayne Jones" <waj at mnsi_net>]

Ed wrote:

I have a question which I have been pondering for some time now. As I am
getting closer to getting a CO2 injection system (I can't wait!), I have
been wondering how much CO2 is actually in the gas(es) given off by a
DIY yeast system. We all know that a canister is much better at getting
CO2 into the tank. Experience (by anyone who uses a canister after a
yeast system) says this is true.

But if one gets the same number of bubbles from a yeast system as a
canister would normally deliver, the results are still not equivalent. I
suspect it is because the actual content of the CO2 in the gas coming
off a yeast system is more in the range of about 50%.

Does anyone out there have any more information than my hunch? What else
may be in these gases? Alcohol? It is just something that I thought
would be interesting to know.

Wayne writes:

The content of the gas from fermentation is nearly 100% CO2. There can
be tiny amounts of other things. Certainly there is a very small amount
of methyl alchohol vapour. Most people do not do well with yeast CO2
because they just don't have complete fermentations or they have leaks
in their system. Leaks often go unnoticed as the lack of CO2 is
attributed to a dead fermentation. There is another major factor that is
hard to get around and that is the fact that a fermentation is
inherently uneven. If you produce just enough CO2 for your tank at the
peak of CO2 production then you won't have enough as the production
fades. If your average production is enough for your tank then at times
you will have too much. That's why you need two bottles no matter what
size your tank is. Even then though you cannot run the CO2 levels as
high as you would with pressurized CO2 or you will run the risk of
getting more CO2 production than anticipated and harming your fish.

Wayne