Many players buying their first paintball gun  are unfamiliar with which Tanks they should be using with their paintball guns. The choice is  between HPA (High Pressure Air) and CO2 (Carbon Dioxide).

Below are some differences, pros, and cons of each gas. While this may show that HPA is nearly always a better choice, it will also point out some of the situations in which CO2 may be  better.

The first difference most players notice is the cost difference between a CO2 tank and an HPA tank. CO2 tanks rarely cost more than R400 , while HPA tanks can run anywhere between R800 to almost R6000 for carbon fiber ones. The higher cost of a High Pressure Air tank may be off putting to a new player from spending more money, however, over the life of a CO2 tank (which is generally 5 yrs.} you will save that money.  CO2 requires the purchase from a third party company. That cost is then passed onto the customer. The average  charge for co2 is R1-R2 per oz to fill a CO2 tank. HPA tanks can be filled form you own Set up using a Dive tank and SCUBA refill adapter. saving you time and money in the long run.


When CO2 is stored under pressure most of it is in the form of a liquid at the bottom of the tank. When CO2 leaves the tank and travels through your marker, it expands into a gas and cools to sub zero temperatures. This rapid cooling can cause the rubber o-rings inside your marker to shrink, harden, and sometimes break. While the damage caused by using CO2 is easily and cheaply replaced, the bottom line is that you will likely have to replace your o-rings more often than you would if you were using HPA.

CO2 tanks must also be removed from the marker in order to be filled, whereas, an HPA tank can be filled while still attached. HPA tanks are filled via a small fill nipple that is not present on CO2 tanks. This means that after the CO2 tank has been filled, you must screw it back into the marker’s regulator while under pressure. This causes the thread wear on both the tank and on the regulator.


Filling a Co2 tank is a lengthier process compared to HPA. With HPA, a quick- connect hose is attached to the fill nipple, it fills for approximately 15 seconds, the hose is detached and you’re done. With CO2, the tank is attached to a fill station and then partially filled. Once it is partially filled, some of the CO2 must be vented from the tank in order to drive the temperature of the tank down, which will allow more CO2 to be filled in the tank. This fill-vent-fill process is repeated until the tank is full, at which point it is removed from the fill station and reattached to the marker. The entire process takes 1 to 2 minutes, and with no real way to tell how much CO2 is in the tank without weighing it. Another drawback to the CO2 system is that there is no gauge on the tank. You could run out in the middle of a game. A gauge on the HPA tank at least indicates when you are getting low.

Pressure – velocity

The output pressure of a CO2 tank is dictated by the temperature of the tank, and on most markers that will have a drastic effect on your velocity. If the tank gets too hot, the pressure rises which causes your velocity to rise, which could result in your marker shooting above the field paintball speed limit and causing injury, or even damage to the marker. More common than that is when the tank gets too cold, as often happens in cold weather or when firing very quickly. When the marker is firing in automatic or simply firing rapidly, the tank cools as it empties. This causes the output pressure to drop, resulting in a drop in velocity. Losing velocity means your paintballs won’t go as far, and might not even break on target, which is a serious disadvantage.

If you’re in the market for a new tank, and still on the fence between HPA and CO2, I hope this helps inform your decision. There are, of course, many different kinds of HPA and CO2 tanks, with different capacities, shapes, sizes, and price tags. Even if you have made up your mind on getting an HPA or CO2 tank, which tank is right for you is entirely up to your personal preference.


Most paintball gun are capable of operating on either HPA or CO2, but there are a growing number of Milsim paintball gun that are HPA only,  using CO2 would cause damage.

CO2 tanks are not capable of holding AIR, and HPA tanks are not capable of holding CO2 – filling either tank with a gas it is not designed to take is incredibly dangerous. The tanks are not interchangeable, and they are not meant to hold anything but the specific gas they were designed for. Adding oil into the tank can also cause the tank to rupture or burst.

All HPA and CO2 tanks have a shelf life, depending on the type of tank and where it was manufactured. The average life span of steel tanks whether HPA or CO2 is approximately 5 yrs.. Tanks are stamped with a date code that indicates the date of manufacture. It is within 5 yrs. of that date when a tank must be hydrostatically tested.  After a tank is hydroed , it is either discarded or a sticker with a new date is applied to it.

If you are new to the sport it is strongly recommended that you buy a NEW TANK  this will ensure that the tank is not damaged or expired. When used properly CO2 and HPA tanks are perfectly safe, but it is important to remember high pressure that is inside the tank. Using a tank that is past its hydro date, damaged, or improperly filled can be extremely dangerous.