I had my propane tank filled in CA earlier this year, and don't know how
much was put in.  I have been using that one tank since then.  I don't use
it a lot, mainly just the stove (though I got the fridge going on propane
yesterday, hooray!).  I went in today to have the tank filled (in CO), and
they couldn't put anything in, i.e. they think the tank is already full.
Maybe the stove is more efficient than I think, but it seems like there
should be at least a gallon or so gone.  So, two questions:

1--Is there a procedure or adapter required that's not in the owner's
manual?  (attach the filling hose, open the bleed valve, fill 'er up)

2--Would it make any difference that the tank was filled at sea level, and
is now at 6,000 feet?  It seems like the filling tank and my tank are two
closed systems, but just thought I'd ask.

Thanks for the help.
bmc  :)
"Faith will move mountains, but you'd better bring a shovel...."