How much time left...

[Two Wheeler]

... When you see this? Last time I didn't notice until it was empty.

[Fhilo]

I wouldn't try to cart a keg but I've served about a keg at this point

[Two Wheeler]

Gotcha, thanks Adam. I'm in the middle of carbing a keg right now so I pulled the tank to get a fill today. Can't run out on Saturday!

[Fhilo]

True dat!

[Jake]

Solution: you'll want to invest in a 2nd CO2 tank to eliminate this risk

[JohnQ]

Solution: you'll want to invest in a 2nd CO2 tank to eliminate this risk

Yup
2 x 20 lb main tanks and a 5 pound "holy crap I've run out knew i should have filled up that other 20 when it ran out" backup tank!

JQ

[brew]

FYI when the tank pressure starts going down, that means there is no liquid left in the tank so she's pretty much empty... like you say probably serve a keg with it...