DIY CO2 Injection

I have already leart that DIY CO2 injection can be made from 2L soda 
bottles and that the mix should be 2 cups of sugar, 1 tsp of baking 
soda and 1 tsp of yeast. I understand the bottle should be filled 
almost to the top with watter then. Besides the composition of the mix, 
does the temperature matter much? I have some of my tanks in 
a rather cold room - the tanks have heater though. And, is it possible 
to kill the fish by injecting too much CO2 - either by making the 
carbon dioxide replace oxygen in watter of by making the Ph drop too 
much? If so, how can I controll how much CO2 is injected with this 
setup? Finally, I understand the CO2 will make the Ph drop. Should I 
counter this by adding some baking soda to the tank watter?



Jan Fidrmuc
CentER for Economic Research, Tilburg University, The Netherlands
P.O.Box 90153, 5000 LE Tilburg, phone: +31-13-466-8221, fax: +31-13-466-3066
Email: Fidrmuc at KUB_NL.