Originally Posted By: DBMaster
Keep a spare tank on hand (filled, of course) and don't worry about gauges or weighing.
Agreed.
OP has 3 tanks, shouldn't worry about running out of propane.
I have 2 tanks, most places in So Cal require minimum of 5 gallon, so I fill empty tank with 3 gallons the other not so empty with 2 gallons. On average we use about 4-5 gallons a year.
The price of propane is varied widely in So Cal, from $2.90/gal to $4.50/gal. The place with low price happened to be close to my house, so it is more convenience and save me few bucks.