What do I need to connect my gas fire pit to a standard 20 lb. propane tank?With a standard 20 lb. propane tank you are limiting the amount of BTU usage to between 90,000 and 100,000. For this reason, the largest ring recommended you use would be 18”, you will also need a regulator and an air mixer along with the other standard supplies necessary (e.g. fittings, valve, key, and piping).