CO2 Tank

[Ceej]

Hey y'all. I'm just getting back into the hobby after being out of it since 2018. I've got a CO2 tank and regulator that I used back then, but I didn't run the tank empty. So question is, should I return to where I filled it and get it refilled, or use it how it sits right now? Would the remainder of the CO2 leak out over the course of the last 4 years?

Thanks for your advice!