This is a test of commonsense. Complete the next sentence:

How to buy propane
Determine what your propane tank is for.
Whether you purchase a propane tank or lease one, the best way to start narrowing down your choices is by asking yourself what you need propane for. It can be used for drying clothes, heating your home, and cooking, among other things.
Make a list of all the things you do that are going to use propane for and then determine the range of propane usage you need. Choose a 4.7 gallon (18 l) tank for barbeque grills.