"RST Engineering" wrote:

I would ten times over risk gas theft over water condensation overnight
in half-full or nearly empty tanks.

There's not enough water in 20 gallons of air to matter.

How much water is there? In *extremely* wet conditions (saturated air
at 20 deg. C) there are only 14.7 g/kg of water in the air. A cubic
foot of air at SLP weighs about 34 grams at 20 C. 10 gallons is ~27 cu.
ft., so that gives about 900 g. of air and about 14 g. of water. Not a
problem.

--
Dan
C172RG at BFM