CCK offers a CO2 tank exchange for $20. We take your empty CO2 tank and provide you with a full CO2 tank. We do not currently require CO2 tank security deposits, as we do with kegs, and we do not keep a large supply of tanks to be able to supply spares to our keg accounts.   If you would like a spare CO2 tank, you can purchase one and we can do a swap for you anytime it is needed. If you need assistance sourcing the equipment, please email us at team@crossculturekombucha.com.