Re: Power head or bell?

>From: olga at arts_ubc.ca
>So what's the word out there? Is it better to collect CO2 in an upturned
>half bottle or to run it through a power head?

It all depends on your setup.  The idea is to dissolve all the CO2 if possible.

>There are oxygen bubbles under the plant leaves and lots of (what I assume
>is) CO2 bubbles floating just under the surface and coming out of the power
>head output. How come all this CO2 never lowers my pH anymore? It used to

If you have CO2 bubbles coming out and rising to the surface, then you're
wasting CO2.  I have had luck with injecting CO2 into the intake of a
canister filter.  No bubble at the output end, which means the CO2 is
completely dissolved in the filter.  I have also used a homemade bell, and
aimed the filter output at the CO2/water surface under the bell, constantly
agitating it.  That worked also.

>From: "Yen, Yimeng" <YYEN at biochem_medsch.ucla.edu>
>Date: Mon, 12 Feb 96 22:44:00 PST
>Subject: CO2 Questions
>Hi, I have a 10 gallon tank which I am using as my "first" plant tank.  I am 
>currently using a DIY yeast reactor (1 cup sugar, 2 tsp yeast) to provide the 
>CO2 for my tank.  I realize that the amount of CO2 is probably impossible to 
>control for this type of reactor.  I read all sorts of posts about how people 
>can get good bubbles with their reactor and I wonder how they do it.  My CO2 
>only seems to bubble for 4-5 days.  In the beginning, CO2 is coming out of 
>the reactor manically.  In fact, I lowered the pH 1.5 - 2.0 points within an 
>hour (something my plants love, evidenced by a TREMENDOUS increase in O2 
>production), but something that my fish hate me for.  After 3 days, the 
>bubbling dramatically decreases.  Am I using the wrong kind of yeast?  I'm 

You are using the same kind of yeast I'm using.  And the result is very
logical from what you described.  You're using too much yeast.  Too much
yeast means the sugar will be eaten up quickly, resulting in a lot of CO2 in
a short time.  Reduce the yeast for a slower, longer lasting CO2 supply.  I
use only 1/2 teaspoon for 1 cup of sugar.  You'll have to experiment to find
the right doseage for your needs.


                     Hoa G. Nguyen  
NRaD Code 531                    Email: nguyenh at nosc_mil 
San Diego, CA 92152-7383         Ham:   KF6YP