CO2 regulators

Subject: CO2 regulators

> One thing I cannot understand is why some CO2 regulators have tw
> gauges, CO2 is a liquid in the bottle and so the input pressure 
> same pressure untill the bottle is completely empty, at which ti
> You will know this anyway, as no gas will escape when you open t

> So only buy a regulator with a gauge on the output side of the r
> gauge on the input side is a waste of time. (and money)

Almost right.  At the level of CO2 that we use in a tank, you will 
also go through a brief period (for me it's about a week) where 
the liquid CO2 is exhausted, and you are left with the dropping 
pressure of the gas that's left in the cylinder. (Remember that 
the high pressure is what kept the CO2 in its liquid state to 
start with.  A quick check of the gague lets me know whether I'm 
getting close to the end of my supply.  When I see it begin to 
drop, I know I've got about a week to get it filled without 
running out completely.  It's also good for vacations.  As long as 
it's at full pressure when I leave, I know it will hold out till I 
get back.
Karen Randall
Aquatic Gardeners Assoc.
Boston, MA