Re: impurity released in an aquarium by using an 'home made' reactor

Dear questioner,

Yeast use sugar as a source of energy in the absence of oxygen, in a 
process called fermentation.  In this process the sugar (usually sucrose if 
"household sugar" is used) is first converted to glucose, then the glucose 
is broken down into ethanol (alcohol) and carbon dioxide.  The simple 
equation for this is:

C6H12O6 ----> 2C2H5OH + 2CO2

No other gases are produced by yeast during fermentation and so the CO2 
produced will be pure.  Provided that the fermentation reaction is well 
isolated from the aquarium, there should be no other contaminants.

Neil Saunders