CO2 Tank-Never used

I now someone with a new aluminum tank it's 5 lbs stands about 18-1/2" tall, 5-1/2" it's for a beer meister or mig welder they got it for free and want $40 for it. Currently I have the window for my co2 so that's even better I suppose. I was thinking down the road if I was not within windows reach or if it's better to use I'll close the window and run the tank. Since it's just the tank what attachements would I need and what's the settings for it?

Co2 works best in a sealed room, when all fans are turned off for the CO2 application. Then after an amount of time, the CO2 turns off and the fans start back up.
You will need a regulator, distributing hose, a timer, and a valve that can open and close the CO2 flow by using a timer. If you have the cash, a CO2 monitor controller will open and close the CO2 as needed automatically.

CO2 via a bottle gets expensive. Most say if your not running high temps, that CO2 doesn't make sense due to the cost.

Thanks for the help Dirty.