Is there any good reason not to use a O2 regulator on a CO2 cylinder ? I live is South Africa and CO2 regulators are +- $150 where as I can get O2 regulators for +- $60

As I understand it O2 is at higher pressure, and more corrosive than CO2 and as such the regulator should be fine ? The only reasoning I can see not to use a O2 regulator is that the CO2 cools quite rapidly if the regulator is opened fully and that might cause a problem if the regulator gets to cold.

Any one that is more knowledgeable know why I shouldn't

Phillip Grobler

I don't know of any safety issue but the first problem is getting the regaultor attached to the tank. The standard CO2 cylinder uses a different fitting than does an oxygen cylinder. As far as freezing the regulator, that should never happen since the flow rates of CO2 are exceptionally low.

CO2 regulators are used for soda dispensers and beer. There is usually a good supply of them available from those applications and they are perfectly suitable. If you look around I am sure you can find one. The tricky part is getting a decent needle valve that is capable of regulating the low flow rate that you need. The kits that are made for aquaria usually combine a bubble counter, solenoid, and needle valve with the regulator so you get some value from those extras.