Re:CO2 regulator suggestions
I use a 20 pound CO2 cylinder, topped off with a regulator (purchased from
a local beer-brewing supply for $45) and a NuPro needle valve (mentioned in
the FAQ and purchased from a local valve supply for $35). It's a manual
system--no solenoid. I do not believe it is necessary.
The regulator has two manometers, one for cylinder pressure and one for
output pressure. The regulator's control valve is not precise enough to
consistently produce the 1 bubble/second flow I want, and that is what the
needle valve is for. It has a micrometer-like adjustment that can
accurately dole out any flow rate from one bubble/minute to empty the
cylinder/minute. It even has a set screw to prevent my three year old from
making unauthorized adjustments.
I keep the output from the regulator to the needle valve at 30 psi. Needle
valves need a fair amount of incoming pressure (>10-15 psi) to work
properly. Regular airline tubing then runs from the needle valve to my
I'm sure the Dupla equipment works just fine, but I cannot imagine a BETTER
manual system than mine, especially for the price.