The solution to CO2 regulation is to get a regulator with an
extremely low pressure second stage.  Based on my current experience,
I would say 0-5 psi full scale.  To do this find someone who rebuilds
regulators and ask them to build you one custom with a very weak
spring and low range gauge.  Then you can run your CO2 at 1-2 psi and
handle it just like the output of an air pump.    Dave

Dave Gomberg, FormMaestro!      San Francisco CA USA   gomberg at wcf_com