Gas-powered devices such as paintball guns and keg systems require pressurized CO2 in order for them to work properly. The tanks containing this pressurized gas come in a variety of shapes and sizes, and need to be refilled regularly. There are a number of places you can get a CO2 tank filled up at; however, if you are going to be using a lot of CO2, it might be a wise investment to get your own fill up station for your home.
CO2 tank
Dual valve fill station
Scale
50-lb. CO2 bulk tank
Purchase a 50-lb. CO2 tank with a siphon tube, a scale that can weight up to 5 lbs., a fill station with a dual valve to allow you to fill up and empty tanks. Bulk CO2 tanks and the rest of the equipment can be purchased online or ordered through paintball retailers.
Secure the 50-lb. tank somewhere secure like a basement corner or attached to a workbench. Place the small plastic ring that came with your fill station between the tank nozzle and the fill station.
Check the hydrotest date on the tank you wish to fill up to make sure it hasn't expired.
Empty the tank you're filling by attaching the siphon tube to it, loosening the release valve on the dual fill station and opening the valve on the tank you wish to empty.
Place the empty tank on the scale and zero the scale so you can figure out how much gas you're putting into the tank.
Chill the tank before filling it by putting about 1 or 2 oz. in the tank and then letting it out by opening the purge valve. This preps your tank so that you can safely get the most gas in there.
Fill your tank by opening the valve on the bulk tank. Make sure you don't actually fill your tank to capacity as this could be dangerous. Instead, fill it to about an ounce or two short of its maximum capacity, which should be labeled on the side.