I acquired a 5# CO2 bottle from a Fire extinguisher repair outfit. I bought a used CO2 fire ext. It cost me $25.00 canadian. I also had to buy a CO2 valve for it which also cost me $25.00 can. Just make sure that the bottles' test date is still valid. The actual CO2 is very inexpensive, about $5.00 Can. for 5#. Paul. Lesniak