I am new to RV'g and have 2 tanks in my 5th wheel. We have had one tank go dry, but not both. Our BBQ grill has a gage at home, it is not very accurate. I have run out in the middle of a party. We have looked for gages and there does not seem to be anything other than the BBQ gages. We have heard about the water test, which is running hot water down the out side of the tank and the water will bead up when it hits the line where there is gas.