A couple posts I read today got me thinking...why not use a standard low pressure propane regulator to supply CO2 to a fermenter during a cold crash?. Turning a standard CO2 regulator down that far doesn't really work but these are designed to work reliably at 11" WC (about 0.4 PSI) which would be fine for about any fermenter. The regulators run about $10. Probably spend more than that on fittings but it seems like the whole thing could be built for under $25, maybe under $20. Anyone try it before?