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Paintball Air Systems - The Difference Between CO2 and Compressed Air Paintball Tanks

Everything You Wanted to Know About CO2 and Compressed Air/Nitro/HPA Paintball Tanks.

Maddog 20 oz CO2 Tank  Empire Compressed Air tanks left to right, 88/4500, 68/4500, 48/4500


Paintball Tank Sizes:

CO2 paintball tanks are used in a variety of sizes, from 12 gram disposable cartridges for paintball pistols and CO2 powered airguns, to 9, 12,16, 20, and 24 oz refillable tanks. Refillable CO2 tank numeric values reflect the liquid capacity of the tank, most comparable to glass sizes. For instance, a 20 oz tank is a little bigger than a pint from the local pub while the 12 oz tank has about the same volume as a coffee mug, with a taller thinner cylindrical shape. The larger the CO2 tank the more shots you can take before having to refill. It is best to choose a tank size comfortable for you. The 20 oz tank offers a balance of capacity vs tank size/weight that works well for most people. offers 20 and 12 oz CO2 tanks from the brands Maddog, Tippmann, and Valken. We do not offer disposable CO2 cartridges, 9, 24, or any other size CO2 tanks beside 12 and 20 oz.

Compressed Air tanks are described in size by a ratio of cubic inches per pounds of pressure per square inch, for example the Maddog Compressed Air 48/3000 tank is 48 ci and safe to fill to 3000 psi. The general standard for air efficiency is about 10 shots per cubic inch at 3000 psi and 15 shots per cubic inch at 4500 psi. Compressed air tank sizes range from 13/3000 to 100/4500, this wide range includes a variety of lengths and shape configurations to fit the individual’s needs. Paintball Deals offers tank sizes include a 48/3000, 48/4500, 68/3000, and 68/4500.

Paintball Bottle Composition:

CO2 tanks are made of a combination of Aluminum and Steel.

Compressed Air tanks rated at 3000 psi are usually made of aluminum, while tanks with a pressure rating of 4500 psi are made with a supportive wrap usually composed of carbon fiber.

What is CO2?

CO2 is a waste product of cellular respir.... just kidding, in paintball, Carbon Dioxide (CO2) is used to power the marker. CO2 is directed through the paintball gun when it is fired.

CO2 is a gas under normal environmental conditions, in order to use it for paintball, CO2 must be cooled and condensed into a liquid. 

OUTPUT: Varies upon conditions, about 850 psi. 

CO2 is most commonly used for mechanical paintball markers that have very little to no electronic internal components. For example the Tippmann A-5 with the response trigger is completely mechanical, but the Tippmann A-5 with the e-trigger has electrical components that could wear out more quickly when using CO2 so it would be best to operate with compressed air. 

For your specific marker refer to the owner's manual to check if it is compatible with CO2 or requires the use of compressed air.

If the marker uses a battery, then it likely requires compressed air. The air system you choose will not affect the hopper. Therefore an electric hopper will not be affected by the choice of air system. One anecdote, If using a Tippmann with a cyclone feed, low output regulators may have difficultly powering the marker, cycling the bolt, and spinning the cyclone feed. 

What is Compressed Air?

Compressed Air is exactly that, air forced into a container. The amount of air within the container increases as it is forced into the limited volume of the tank and as a result, the pressure builds up. Unlike liquid CO2, compressed air is a mixture of gases and does not change physical state to be used for paintball.

OUTPUT: Some tanks have regulators which can be adjusted to output different pressures. The tanks offered by have regulators with a standard high output of about 850 psi. Some markers require low output of 450 psi to work correctly. With too little air pressure some markers may not propel the paintball the proper distance. Additionally they could fail to cycle the bolt, these are signs that you are low on air or CO2. In general, paintball markers offered by operate best with a high pressure output from a compressed air tank.  

Exposing your marker to exceedingly high output pressures can cause the internal components to wear out at an accelerated rate.


How to read the different certification stamps; PI, DOT, TC. 

The different stamps on paintball tanks refer to the type of certification that the tank has received from regulatory bodies. These stamps indicate that the tank has been tested and approved for use in specific applications.

  1. PI (Pressure Vessel Institute) stamp: This stamp indicates that the tank has been tested and certified by the Pressure Vessel Institute to meet specific standards for pressure vessels. This stamp is commonly found on HPA (High Pressure Air) tanks used in paintball.

  2. DOT (Department of Transportation) stamp: This stamp indicates that the tank has been tested and certified by the U.S. Department of Transportation to meet specific standards for transportation and storage of compressed gases. This stamp is commonly found on CO2 tanks used in paintball.

  3. TC (Transport Canada) stamp: This stamp indicates that the tank has been tested and certified by Transport Canada, the Canadian equivalent of the U.S. Department of Transportation, to meet specific standards for transportation and storage of compressed gases. This stamp is commonly found on CO2 tanks used in paintball.

It's important to ensure that your paintball tank has the appropriate stamp and certification for the type of gas it will be used with. Using a tank that does not meet the appropriate standards can be dangerous and is not recommended.

What is the born date of a paintball tank?

The born date of a paintball tank is located on the neck of the bottle of the tank and is important as it lets the user know how old it is. Most paintball tanks have a 5-year hydro cycle meaning the tank will not need to be re-hydro tested until 5 years after its born date. The hydro cycle of a paintball tank refers to the process of hydrotesting, which is the periodic testing of a compressed gas cylinder (such as a CO2 or HPA tank) to ensure its safety and reliability. The hydro cycle of a paintball tank typically involves the following steps:

  1. Visual inspection: The tank is visually inspected for any signs of damage or corrosion.

  2. Hydrotesting: The tank is filled with water and pressurized to a specified pressure, which is usually higher than the maximum operating pressure. This is done to test the tank's ability to withstand high pressures without leaking or rupturing.

  3. Drying: After hydrotesting, the tank is drained and dried to remove any residual moisture.

  4. Re-certification: If the tank passes the hydrotest, it is re-certified and stamped with a new hydro-date, indicating the next due date for hydrotesting.

The hydro cycle is an important part of maintaining the safety and reliability of paintball tanks, as it ensures that the tanks are free of leaks or other defects and are in good working condition. 

Parts of a Paintball Air Tank:

Threads: CO2 tank attachment point to the paintball marker. All CO2 tanks must be removed from the marker in order to be refilled. An O-Ring form the seal between the tank and the marker once the tank has been screwed in and the pin at the top and center of the tank is engaged with the marker and allows the flow of CO2 into the marker from the tank. 

Compressed Air threads are attached to a regulator, fill nipple, and pressure gauge. On the regulator is the fill nipple, this is the most sensitive part of the and needs to be protected. It allows the compressed air tank to be filled without unscrewing it from the marker. A compressed air tank has been filled when the needle in the gauge points to the 3 for 3000 psi tanks and between the 4 and 5 for 4500 psi tanks.  

Labelled Paintball Regulator



Am I Allowed to Fill Up My Own Tank Without Assistance?

All air tanks, regardless of system type, are shipped empty per Department of Transportation. An empty tank will not engage with a paintball marker. Please make sure you fill the air system before attempting to use it with a paintball marker. 

CO2 tanks have to be filled by a qualified technician. Paintball size CO2 tanks are filled from larger volume liquid CO2 cylinders. These larger fill containers are susceptible to self propulsion and explosion if handled improperly. For safety reasons it is imperative that CO2 tanks be emptied completely before filling too. CO2 tanks are weighed before and after to gauge the amount a CO2 tank has been filled.

Filling Compressed Air tanks is simple and safe enough for patrons to do. Once the fill hose is connected to the compressed air tank via the fill nipple, a lever activated at the fill station will vent air under high pressure into the compressed air tank (lower air pressure) until the containers are equalized to the same pressure. Releasing the fill lever prevents the further passage of pressurized air from the fill station to the tank. Allowing for easy separation between the compressed air tank and the fill station. A small amount of pressurized air within the fill hose will escape upon detachment from the fill station. There will be a short loud hissing noise upon detachment, this is completely normal. 

There are separate fill stations for each pressure rating. One will be 3000 psi and the other 4500 psi. 

*WARNING*: Compressed air tanks with a 3000 psi regulator should never be filled above 3000 psi. Be sure to use the appropriate fill station when filling tanks with a regulator rated for 3000 psi.

Tanks with regulators rated for 4500 psi should never be filled above 4500 psi. It would be unusual to find a field's fill station set to anything greater than 4500~4600 psi. You can use the 3000 psi fill station, but it will not completely pressurize the tank only "filling" it to 3000 psi.

Accessories for Tanks:

Additionally compressed air tanks can be filled from Scuba tanks with the use of a compatible adapter and fill hose. offers the Maddog Scuba Fill Kit allowing you to refill air tanks from a SCUBA tank. This is ideal when you are playing woodsball and do not wish to make a trip to the sporting goods store to refill on compressed air.

Scuba Fill for compressed air tanks



Damaged tanks, both CO2 and Compressed Air, cannot be repaired or filled. Cover your tank and its nipple. Extend its life, insulate it, and play with it.


Tank Cover
Maddog Remote Coil
Nipple Fill Covers


Remote Coil: Standard remote coils allow for the removal of the air system from the marker onto a harness or vest. The remote coil connects the marker to the tank via a durable flexible hose. The standard version requires the disengagement of the coil from the tank when removing the air system. Remote coils can be used with both CO2 and compressed air tanks. 

Slidecheck Remote Coil: This version of the remote coil is functionally the same as the standard. The slidecheck allows the user to remove the air system from the marker without having to disengage from the air system. 

 Push Button Remote Coil: Allows for quick disconnect between the remote coil and the marker without disengaging the remote coil from the paintball tank. 


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