Can you Fill A CO2 Paintball Tank With Compressed Air?

Surely, you want to get out and have fun with your paintball gun, but you can’t until you figure out how to best equip it. There is a lot of uncertainty surrounding how to use different pressure sources in a paintball gun. Moreover, determining whether you can fill a CO2 paintball tank with compressed air can be difficult. But don’t worry, as I have done the research to help you. 

Theoretically, you could do this, but it is recommended that you refrain from cross-filling tanks. A major safety concern with cross-filling tanks is tank explosion, resulting in bodily injury. Doing this could also negatively affect paintball gun performance. 

Unfortunately, there is a lot of conflicting information out there concerning this topic. Read on to find out why it’s not recommended to fill a CO2 paintball tank with compressed air, how to appropriately use compressed air in your gun, and more.

How to Fill Your CO2 Tank with CO2

For paintball enthusiasts who want to create their own home refill station at home, this section is for you. 

Here’s what you’ll need: 

  • Dual Valve Fill Station
  • Your CO2 Tank
  • Scale
  • Standard Crescent wrench
  • 20 or 50-pound Siphon CO2 Tank (where you will be getting your CO2 from)

You can get all of these from Amazon (table below). You probably already have a scale lying around somewhere. The big refill CO2 tank can also be smaller (and cheaper) than I recommend, just keep in mind you will need to refill the gas into it more often then.

Tip: Make sure that your tank is already cold before refilling it. You can refrigerate it or use the fill system to cool the tank down. 

  1. Secure your 50-pound siphon CO2 tank onto a workbench. 
  2. Place the plastic ring (the one that came with your fill station) between the tank nozzle and your fill station. 
  3. Verify that your hydro test date on your tank has not expired. 
  4. Empty your tank by attaching it to the 50-pound siphon tank. You’ll loosen the release valve on the dual fill station and open your tank’s valve. 
  5. Place your tank on the scale and zero it out. This is so you know just how much gas you’ll be putting into the tank. 
  6. Chill your tank by dispensing one or two ounces of CO2 into your tank and then let it out by opening the purge valve on the fill station. This is prepping your tank so that you can get a max fill. 
  7. Now you can fill your tank by opening the valve on the bulk tank. 

Tip: Don’t fill your tank to the max. Instead, fill it one or two ounces short of the max. 

Here is a video on Youtube that explains how to fill your CO2 tank step by step.

YouTube: How to fill your CO2 tank

Concerns With Filling A CO2 Tank With Compressed Air

It is never a good idea to put gas in a tank that was not designed to hold that gas, and I’ll tell you why. There are several issues that have the potential to arise when filling a CO2 tank with compressed air. These issues should not be ignored, as they affect both you and those around you. 

Shooting Issues

The main reason that people want to use compressed air in their guns is that doing so would improve their gun’s functionality. However, using compressed air in the CO2 tank of a paintball gun is not guaranteed to have the same effect as using compressed air in an appropriate tank. 

You could fill your CO2 tank with compressed air and find out that your gun’s fire rate has slowed or even stalled completely. This could completely derail your paintballing fun. To avoid shooting issues, it’s important not to put compressed air in your CO2 tank.

Tank Explosion

Perhaps the most alarming consequence of cross-filling your paintball tank is tank explosion. Yes, your entire tank could explode due to the pressure of the compressed air. When the explosion happens, both you and others around you could be injured. 

For good reason, paintball tanks are engineered differently for the specific gases they will be filled with. This is why you have CO2 tanks, and then you have compressed air tanks.

The Best Way to Use Compressed Air For Your Paintball Gun

As I touched on earlier, it is generally advised not to use compressed air in your CO2 tank, due to the many dangers involved. The best way to use compressed air for your paintball gun is to switch to a compressed air tank and get that filled with compressed air. 

Since compressed air tanks are the only tanks designed for compressed air, there are so many variables between the compressed air tank and the CO2. It is virtually impossible to fill a CO2 tank with compressed air without subjecting yourself (and those surrounding you as you paintball) to serious danger. 

Before putting yourself and others in danger, it is imperative to familiarize yourself with some pertinent information on pressure sources for paintballing. 

Next, we will examine CO2 and compressed air as they related to paintballing. This will help you to determine with certainty which pressure source you want to use for your paintball gun. 

Background on CO2 and Compressed Air

There is only one way that CO2 and compressed are similar. Both CO2 and compressed air make a paintball market cycle and launch a paintball out of the barrel of your paintball gun. There are way more differences between these two gases. Let’s look at them separately. 


CO2, which stands for carbon dioxide, has been the standard in pressure sources for low to mid-range paintball guns for some time. The pressure (created when liquid CO2 turns from liquid to gas) is the catalyst that fires the paintball. 

There are two types of CO2 tanks: refillable CO2 tanks and disposable CO2 tanks. As you can imagine, the refillable CO2 tanks can be used multiple times, and the disposable CO2 tanks are to be used once and thrown away. Refillable tanks are made of aluminum and have a valve for refilling.

The very first paintball guns, like the Nelspot 007 and NSG splatmasters used CO2. 

Let’s look at the benefits and drawbacks of using CO2 for your paintball gun. 

CO2 Advantages


It’s tried and true, being that it was the first-ever pressure source for paintball guns. Most players are generally familiar with CO2, how to refill it, how to use it, and they know that this pressure source is dependable. Using a well-known pressure source means fewer questions and more shooting. 


CO2 tanks are cheap, enabling players to buy several disposable tanks (or refill their refillable tank multiple times) for heavy shooting play that lasts all day. In the U.S., a CO2 tank refill costs right around $5. This is likely the top reason that CO2 has been popular for so many years. 


Paintball pro shops often will refill your CO2 tank for you. And if you need a CO2 refill but you don’t have a paintball pro shop in your area, sporting goods, welding, and fire extinguisher supply shops can fill your CO2 tank (at their discretion, of course). This is a convenience that you don’t get with compressed air. 

Design of CO2 Tanks 

When it comes to the design of CO2 tanks, a benefit is that CO2 tanks have a compact size. And for their compact size, the CO2 tanks yield a lot of shots compared to the alternative (compressed air)

CO2 Disadvantage

Tank Chilling/ Gun Chilling

The main disadvantage of using CO2 is the common phenomenon of tank and gun chilling. 

Why is this a problem? 

Well, when a player is shooting a paintball gun filled with CO2, several things happen in the heat of the game. 

As liquid CO2 expands, enabling a player to release a paintball, the CO2 cools. As the player continues to shoot out paintballs, the CO2 cools even further, eventually affecting the gun’s firing range. Also, the cooling frenzy that’s created when CO2 gets too cool also affects the gun’s accuracy. 

If you’ve ever gone paintballing before, you may have noticed something similar to snow coming out of the barrels of the paintball guns. This isn’t snow. It’s liquid nitrogen, created when CO2 cools extensively. 

Compressed Air

Compressed air is also known as HPA (or high-pressure air). It’s used in many mid to high range paintball guns. There are two main types of compressed air tanks, and these are aluminum (which holds 3000 PSI) and carbon fiber (which holds about 4500 PSI). Compressed air has many benefits, as well as a few drawbacks. 

Compressed Air Advantages

Consistent Pressure

The main advantage of using compressed air in paintball guns is that compressed air provides consistent pressure within the paintball compressed air tank. This is because compressed air is not affected by weather or temperature, like CO2. This means that the gun will perform at its absolute best on compressed air. 

Increased Accuracy

Due to the consistent pressure that compressed air provides, players, enjoy increased accuracy. This makes for much more competitive shooting. When using compressed air, players can rest assured that their play is not being negatively affected by their pressure source, whereas with CO2, the accuracy could be negatively affected. 

Top Range

Compressed air is known to give paintball guns long-range shooting capabilities. This is an extremely valuable asset to any paintball player. Unlike CO2, where the range can be affected by the cooling/freezing of the CO2 liquid, paintball guns equipped with compressed air can fire paintballs at the top range. 

Long-Range Cost

It costs anywhere from 1-3 dollars or more per 1,000 PSI to refill your compressed air tank at a paintball pro shop. For some, that may be a little steep, especially if you paintball often. However, you get more overall shots out of compressed air than you get with CO2. 

Compressed Air Disadvantages

While compressed air is the best pressure source for your paintball gun, it can be difficult to find someone who will refill your compressed air tank. Unless you have a paintball pro shop in your vicinity, you’ll have a hard time finding a place with the equipment and personnel available to get your tank refilled. 

Tanks Are Not Compact

Compressed air tanks are not very compact. This is not an issue with CO2 tanks, which are often quite compact. The main issue that comes with compressed air tank design is the overall bulkiness of the gun with the compressed air tank attached. This is something that some players get used to, but many find this to be an issue. 

Short-term Cost

Compressed air tanks are considerably more expensive than CO2 tanks. This discourages some from purchasing them at all and limits others who would like to refill and play more often. 

Which Is Better? CO2 or Compressed Air? 

When trying to find the answer to the question: “Which is better? CO2 or Compressed air?”, one must consider all of the advantages, disadvantages, and their personal preferences. 

Compressed air is known to be an option that allows for higher accuracy and longer range shooting. CO2 is most used for its affordability and lightness (it’s easier to carry around while paintballing). 

So, if we are focusing on gun performance, compressed air (in a compressed air tank, of course) would be the best option for players who are concerned with having max accuracy and long-range shots. These are very important to have when playing competitively. 

Conversely, for those who have money limitations and are just paintballing for fun. CO2, even with its flaws which cause slower to stalled firing, will likely be enough to do the job. Also, if you are using CO2 and your opponents are also using CO2, then everyone will be on a level playing field. On the other hand, if you are regularly unevenly matched, meaning that you play with people who are using compressed air, you may find yourself frustrated with how your gun operates in comparison. 

How Much Shooting Can You Do With Compressed Air vs. CO2

Another popular question that many ask when they are new to paintballing concerns the volume of shooting that can be done with both CO2 and compressed air. 

Shooting on CO2

The average CO2 tank, 20 ounces, is sold for about $22.00 and can shoot over 1,000 paintballs. This is the appeal that CO2 has on players. Once they find out that they can shoot over 1000 paintballs, they are ecstatic. Oftentimes, people grab a few of these tanks and enjoy the all-day play.

Shooting on Compressed Air

On the topic of compressed air, the average compressed air tank costs anywhere from $40 to $250. It would take a very expensive 68 CI 4500 PSI compressed air tank to be able to shoot 1000 paintballs. This tank costs anywhere from $150 to $200. Other tanks would not be able to meet the output of 20-ounce CO2 tanks. 

When it comes to the number of shots that you can shoot on compressed air and CO2, players have to decide whether they want lots and lots of okay shots (with CO2) or whether they want fewer shots that are high-quality (with compressed air).

Note that not every gun works with either CO2 or compressed air. So, before you purchase a gun, make sure that it can work with both CO2 and compressed air. The general rule is that electronic paintball guns generally only work with compressed air, and manual guns usually work with both CO2 and compressed air. 

Happy Paintballing!

Sometimes there are no cutting corners to get the best of both worlds, and this is the case with paintballing. So keep yourself and others safe by buying the tank that you prefer and then filling it with the gas that it was created to hold.

While it may be an investment, it may be worth it to purchase a compressed air tank and fill it with compressed air.  So, make your choice. Would you prefer CO2 or compressed air for your paintball tank? You’ve got pertinent information on both pressure sources that will help you make your choice.