CO2 tank: Is It Empty? And Where To Get It Filled?

The gauges on the regulator DO NOT tell you how much gas is left in your tank,  it is less like a fuel gauge and more like a fuel light.  The needle will go up or down depending on temperature, NOT on gas usage.

How can you tell how much gas is left in your tank?  On the side of your tank you will have a "Tare Weight" usually indicated by TW with a number in LBS or KG.  It will be imprinted into the metal, near the top.  Next to the TW will be a number.  This is the weight of the empty tank.   The only real way to tell if your tank is empty is to weight your tank;  any weight over the TW is the weight of the gas in the tank (i.e. the TW says 8LBS and you weigh it and it weighs 10LBS, you have 2LBS of gas in the tank).

But, what when you tank is totally empty?  Never despair, Mainbrew can resolve your empty tank dilemmas.  

We do not fill CO2 tanks, however we do have an exchange program: 
Bring in your empty tank and we will exchange it for a full one;  we take your old tank and you own the new tank.  We exchange aluminum for aluminum tanks, and steel for steel.  So you'll receive a tank that looks very similar to your old one.