DIY CO2

I decided to use DIY CO2 for this setup to speed up my plants growth. Both non CO2 and daily Excel dosing does not give enough grow rate.

My DIY CO2 setup is pretty simple:
- 2 bottles of 1.5L soft drink (empty)
- 2 bubble counter
- 2 check valve
- Airstone
- CO2 hose

I did not use diffuser since it may not generate enough pressure to push CO2 through but I put airstone under filter inlets. That way most of the CO2 will be suck in by filter but it may cause airlock in some filter if lots of CO2 is created. Buble counter function as an indicator which bottle need to change. The check valve is to prevent CO2 from leaking out when one of the bottle being replace. I did not premix the solution together at the same time.


Simple sketch


I've been researching through out the net about DIY CO2 recipe and found that wine yeast suppose to be used instead of normal bread yeast. Apparently alcohol is toxic to yeast and alcohol is by product when yeast consume Glucose to generate energy in Anaerobic condition. Wine yeast on the other hand can tolerate highest level of alcohol and acidity. Thus in theory wine yeast will give you longer CO2 generator


Aerobic condition:

Glucose + O2 --> CO2 + H2O + Energy

Anaerobic condition:

Glucose --> CO2 + Alcohol + Energy

Searching around for wine yeast and found out that it cost 10 times more than normal yeast from supermarket. So forget about the idea of using wine yeast and use instant yeast instead (Saccharomyces Cerevisiae) from Bake King

My recipe:

- 2 cup of sugar
- 1/4 teaspoon of yeast
- 1/2 teaspoon of baking soda
- 1000 ml of water

Honestly it really not bad. I was haunted by post on forums, people was saying that DIY CO2 have unstable output. On contrary, I was able to get good stable output at least 0.5 bps for a month.


Update (12 October 2011)
BPS output from 1 bottle through out 37 days.