I don't know the pressure -- I'm using the regulator from an Eheim CO2
system, which has only a single pressure gauge that measure the pressure
in the tank. There is no gauge that shows the pressure after the regulator.

BTW, I've had bad experiences with the Eheim CO2 system, and I wouldn't
recommend it. Almost everything about that system is rubbish, and I ended
up having to replace all of it, except for the regulator.
(snip)


You really should get a regulator (they are quite inexpensive).
That way you can have infinite control over your CO2 output.
I use a 75 lb bottle connected to a 4 port (each port has a valve)
header at the regulator. From there I feed a 1/4" line which branches
off into seperate valves at each tank. My bubble rate for most tanks
(70 gal. average) is 1/sec. Plants and algae are doing great

take care

PS