As some of you may know, I had a thread of mine stickied a while ago about how I built my CO2 chamber. Well just for fun, I thought I'd show you guys where I'm at right now. As my rat production increased, so did my demand for CO2. I found myself having to drive a fair ways to get my CO2 every few weeks, and alot of the time my supplier's fill station was "out of order" aka too lazy to go get the full tank from the warehouse. So I went to my local farm store (TSC), and got a 20lb CO2/Argon tank used for welding. I had to buy a regulator for argon, and an adapter to be put on the regulator to allow me to attach it to the CO2 tank. I then attached a 1/4" (inside diameter) piece of vinyl tubing to the barb on the regular and run it into a trash can. If you use a trash can make sure you have a thin layer of bedding (I use pine) on the bottle to catch all the mess.
Regulator - $50
Argon-CO2 Adapter - $10
CO2 Tank (empty) - $255
Cost to fill tank - $35
Total: $350
Yes I know, very pricey, however, at any time I can return the tank to the store for a full refund. The $255 is really just a deposit of sorts, but they charge so much so you CAN keep the tank if you want to.
And there you have it! Thanks for looking!