How to Fill Paintball Tanks

One of the most neglected/misunderstood parts of playing paintball is how to fill paintball tanks. Whether you are a weekend warrior or a pro rocking the best paintball tank money can buy, you likely hate the process of pulling the regulator out of the tank, removing the line, and then running it through the regulator and back into the tank. What is even worse is having to hook up a regulator and connect the line to your tank, only to find that you are out of CO2 when you try to refill it for the next match.

Here’s how to fill paintball tanks: Paintball guns use either carbon dioxide (CO2) or high-pressure compressed air (HPA). DIY refilling of these tanks can be done with a specialized paintball air compressor or by using a filling station. You can also fill them at various sporting goods and specialty stores.

There are a few DIY ways to refill paintball tanks.The good news is after your initial equipment purchases, DIY can save you substantial money in the long run. If you don’t play paintball often, you can likely get away with refilling at a store near you for a few dollars each time.

Know the Difference Between CO2 vs HPA Paintball Tanks

First, you need to know CO2 tanks and HPA tanks are not interchangeable. Each paintball gun will indicate whether you should use HPA or CO2, and you can ruin them if you use the wrong type.

Refillable tanks for both initially cost anywhere from around $30 up to $80. The higher-end tanks will include adjustable regulators.

CO2 tanks are the most common for newcomers to the sport of paintball. They’re cheaper to buy and refill than compressed air, and they hold about 20 ounces of air.

Compressed CO2 takes liquid form but becomes gas once released from the tank with a pull of the paintball trigger. CO2 is affected by temperature, losing pressure in low temperatures, and increasing in high temperatures.

More advanced paintball players typically use HPA tanks since they generate more power. These tanks contain highly pressurized oxygen, which is less dense than CO2. Therefore, it can be stored under higher pressure. These are more expensive to buy and refill.

Know Your Tank PSI

Regardless of the type of tank you are filling, it is essential to know the PSI of your tank (the amount of pressure it holds).

Each tank will have an indicator telling you what the PSI is.

CO2 tanks max PSI is usually around 1800, while it’s typically 4500 PSI for HPA tanks.

Make sure your refill tool has a similar PSI as the tank you’re refilling from to ensure you can fill it all the way. While it’s tempting to use a home air compressor or the one at your local gas station, these won’t work. That’s because the PSI of these is usually around 180-300. Since the PSI of your paintball tank will be between 1000-4500 PSI, those won’t have enough pressure to do the job.

DIY: How to Fill HPA Tank with Air Compressor

The good news is it’s pretty easy to DIY with an air compressor designed specifically for refilling paintball tanks.

Once you know your tank PSI, follow these steps:

1. Attach to the fill nipple

There will be a visible O-ring on the attachment that connects to your air tank to prevent air from escaping when it is attached. Ensure the O-ring is in place. Otherwise, air will escape, and it will be impossible to fill. 

Pull the attachment collar back to expose the needle. Then plug the tank in through the filling nipple. Jiggle it a little to make sure it’s firmly attached. 

2. Fill the tank slowly

Once the tanks are connected, slowly release air. Do this by pushing the lever or button on the compressor. It is important to do this slowly and intermittently rather than all at once. The gauge needle will begin to move towards the max PSI you’re aiming for. 

3. Watch the gauges

There will be a gauge attached to your paintball gun tank and another on the air compressor. Keep an eye on both of them as you refill your tank. They should both move similarly, creating a check and balance that ensures they’re working correctly. 

4. Don’t “hot-fill”

A hot fill occurs when you fill the tank too quickly by pushing the lever or button too much, causing the gauge to rise rapidly. This can damage the tank and cause you to overestimate how much is in it. After unhooking, the air will get hot, and the gauge will drop. Suddenly, you have no air in your tank because it never filled completely.

5. Release pressure from the air compressor

This is a crucial step to remember. When you are done filling, the air compressor will still have air in it. Use the release valve to let the excess air out. It will make a loud sound, but it’s just the air being released and is nothing to be concerned with. You can damage the tank if you don’t do this before unhooking. 

6. Remove the hose

Once you’ve released the pressure, remove the hose from the nipple. The process is the reverse of what you did to hook it up. Remove the collar and remove the hose from the attachment. 

DIY: How to Fill Paintball Tanks with a Fill Station

A fill station will allow you to attach your paintball tank to either a scuba tank for compressed air or a CO2 tank for carbon dioxide. When your bulk tanks run out, you’ll have to get them refilled, but it will require far fewer trips than if you were filling your paintball tank each time. 

Here are the steps for using a fill station:

Fill station with a scuba tank

1. Attach the fill station to the scuba tank.
2. Connect your paintball tank to your fill station.
3. Ensure the release valve on the fill station is closed.
4. Slowly turn the primary valve to release air into the paintball tank until the gauge shows its full. 

Fill station for CO2 

1. Refrigerate your CO2 tank to stabilize the temperature first.
2. Make sure the fill station is firmly attached to your bulk CO2 tank.
3. Connect the paintball tank to the fill station. 
4. Turn the CO2 tank’s primary valve.
5. Open the station’s valve to let air into your paintball tank until it’s full 

Refill at a Store Near You

Most sporting good stores or paintball shops have compressed air and CO2, so they will usually be your best and easiest option. Additionally, welding, scuba, fire extinguisher shops, and even oxygen supply stores may have tanks.

A CO2 refill for a refillable 20 oz tank will run around $5. HPA refills cost around $3-$5 but can be a bit more for larger tanks.