One of the more important FWC-ATC questions!
For us, the gauge is just, shall we say, somewhat helpful.
For a recent Christmas, as requested, my spousal unit gave me a 50lb hand-held fish scale. Someday, I hope to weigh a fish that tips the scale significantly, but in the mean time, I weigh the propane tank. For us, the tare is about 20lbs, and full, it comes in at about 34lb (approx 4.2 gal). One day we stopped in at Camping World, and they had the thermal strips that you paste on the side of the tank for $1.99. Unfortunately, while both methods work quite well, they both require removing the tank and, that's a PIA
. So, to reference a recent post:
http://www.wanderthewest.com/forum/showthread.php?t=1785&highlight=propane
we've ordered an adapter so when the 5gal tank runs out, we switch to a 1lb Coleman propane cylinder/can (or two) and fill up the next day or so. The up side is that a lot of propane stations now charge by the fill-up, not by the gallon, so we will be filling up an empty tank. U-Haul, by the way, still charges by the gallon.