Came across a full #20 tank by trading a friend one gallon of Maibok for it. He could not tell me if that was really CO2 in that tank, as he did not fill it, he said his Dad found it. It has the right label, is in good condition with no dents, just a little dirty with that lint/grease dirt that tells me it hid in the backroom of a restaurant somewhere beside their soda kegs.
Is there an easy way to tell at home? Or should I just haul it down to my localk ARCET and see if they can tell me?