Activities Sports & Athletics Where Can You Get CO2 Tanks Refilled? Share PINTEREST Email Print Mark Kolbe/Getty Images Sports & Athletics Paintball Baseball Bicycling Billiards Bodybuilding Bowling Boxing Car Racing Cheerleading Extreme Sports Football Golf Gymnastics Ice Hockey Martial Arts Professional Wrestling Skateboarding Skating Soccer Swimming & Diving Table Tennis Tennis Track & Field Volleyball Other Activities Learn More By David Muhlestein David Muhlestein David Muhlestein is a paintball and woodsball enthusiast who has been playing since the mid-1990s and has extensive knowledge of paintball equipment. Learn about our Editorial Process Updated on 02/21/19 Carbon dioxide, or CO2, is filled by moving the compressed liquid form of the gas from a larger tank to a smaller CO2 tank that's often used for paintball. The key to filling the smaller tank is to find a store that stocks the larger tanks and has the appropriate equipment to fill the smaller tanks. The type and size of the tank being refilled matters when seeking the most appropriate place to have it refilled. Paintball Stores and Fields Smaller tanks (from about 9 to 24 ounces) used for air guns, such as paintball guns, are a popular size for CO2. One of the best places to fill this type of tank is at a paintball store or a paintball field. Most stores and fields stock CO2 and have all the appropriate equipment to adequately fill without overfilling your tanks. Sporting Goods Stores Many local or national sporting goods stores often fill CO2 tanks for paintball guns. Sporting goods stores are easy to find and usually do a great job at filling tanks, though if you get an inexperienced person helping you, there is the risk that they will overfill your tank, which can result in a burst safety disk. Many sporting goods stores also sell smaller, pre-filled canisters that can serve as great backups for paintball guns. These small canisters also can be found at most bicycle shops. Cyclists often carry them as a quick means to fill a bicycle tire. Fill Tanks at Home If you use a lot of CO2, whether it's for paintball or some other hobby, it might be worth keeping a large tank at home along with the proper supplies to fill smaller tanks. This may save money in the long run, and it also might be more convenient. Tank Exchanges Much like with propane tanks for backyard grills, some stores that sell CO2 tanks also have tank-exchange programs that allow you to drop off an empty tank and leave with another one that's pre-filled. While this might be slightly more expensive than refilling a tank, it can be more convenient. Other Uses for CO2 Home-brewed beer continues to grow in popularity, and one of the ways to add carbonation to the beer is through forced carbonation. This process involves adding CO2 to kegged beer over an extended period of time, as opposed to using sugars to naturally carbonate the beer. These types of CO2 tanks are much larger than the smaller ones used in air guns, as they typically range in size from about 2.5 pounds to 20 pounds. Most any store that sells supplies for home brewing also should be able to refill CO2 tanks. CO2 tanks are also used with a lot of home aquariums that maintain live freshwater plants. While plants can thrive in the proper conditions without additional carbon dioxide being added to the tank, their health and growth benefit greatly from aquarium setups that include the use of CO2. Because of this, many specialty aquarium shops also are equipped to refill tanks.