Propane tanks are not filled completely with the liquid propane as there has to be expansion room when the tank warms up and the gas evaporates for use from the fluid.
I use a 10 pound tank for the Q120 we use on the road. That is easier for me than the 20 or 30 pound sizes. I think the small tank could last almost all summer.
WBCCI Life Member 5123, AIR 70341, 4CU, WD9EMC
TV - 2012 Dodge 2500 4x4 Cummins HO, automatic, Centramatics, Kelderman level ride airbag suspension, bed shell
2014 31' Classic model 30 twin beds, 50 amp service, 900 watt solar system, Centramatics, Dill TPMS, disc brakes, 16" tires & wheels