There are two types of propellants used to power a paintball gun — Co2 and HPA.
HPA (High Pressure Air) is quickly becoming the go-to standard for paintball players to use, but some players still prefer Co2 and that’s okay.
Below I’m going to teach you the pros and cons of Co2 and HPA, where to get your Co2 or HPA tank refilled, how to refill your Co2 or HPA tank at home, and other important information regarding Co2 and HPA that every paintball player should know.
Let’s get to it.
Co2 vs. HPA: What’s The Difference?
If you’re new to playing paintball then you may be confused on whether or not you should use Co2 or HPA. To help make this decision as simple as possible, I’m going to teach you the most important differences between the two paintball gun propellants.
Co2 (Carbon Dioxide)
Co2, or carbon dioxide, was the first type of propellant used to power paintball guns. And while Co2 does have its fair share of drawbacks, it has its advantages as well.
The main drawback of using Co2 to power a paintball gun is that it can cause damage to the internals of your marker. This is because traces of liquid Co2 are going through your paintball gun every time you rapidly fire your marker or when it’s cold outside.
The reason liquid Co2 is going through your marker every time you fire rapidly or when it’s cold outside is because of how Co2 transitions from a liquid into a gas — through expansion. And every time liquid Co2 expands from a liquid into a gas, its temperature drops at the same time. The faster this expansion happens, the lower the temperature drops.
Eventually, you may even notice white clouds coming out of the end of your barrel or frost on the outside of your tank and barrel. These white clouds are dry ice and are definite proof that liquid Co2 is going through your marker.
Bonus Tip: The optimal temperature to use Co2 in a paintball gun is 75°F.
Another downside of using Co2 as a propellant in paintball is that your output pressure drops the faster you shoot your marker. And if you shoot your marker too fast, you’ll eventually notice a loss of range and the marker could temporarily stop firing altogether.
Fortunately, Co2 does have one big advantage over HPA and that is that your initial investment will be much lower. It only costs around $25 – $30 to buy a 20oz Co2 tank and between $3 to $6 to fill up the tank and you’re ready to play (considering you have a marker, mask, paintballs, etc.). A 20oz Co2 tank holds enough pressure for 1000+ shots, so it’s great for backyard players who want to play without spending a ton of money.
HPA (High Pressure Air)
HPA is nothing more than air that’s been pressurized into a tank, which is why it’s called “High Pressure Air”. The benefit of using HPA to power a paintball gun is that the output pressure is much more consistent and therefore better for the internals of your marker. In fact, many high-end paintballs guns can only function on compressed air and will break down if operated with Co2.
The main downside of using HPA is that it can cost anywhere between $50 to $250 for the tank just by itself. Fortunately, most paintball fields will give you unlimited refills for the day with the price of admission. Some paintball fields will even include unlimited Co2 with their entry fee, but other fields will charge for each and every fill. Some paintball fields (such as my local field) have even completely moved away from using Co2, as compressed air is both cheaper/easier to refill and better for their markers.
Where to Refill Co2 and HPA Tanks
Depending on if you use Co2 or HPA will determine where you need to go to refill your tank.
The best place to refill a Co2 tank is a paintball field or sporting goods store, but you can also refill Co2 at some scuba, welding, homebrew, and fire extinguisher shops. Many sporting good stores also have a Co2 tank exchange program where you can buy one of their pre-filled tanks and come back and exchange it for a new one at any time. Some paintball fields will refill Co2 tanks as well, but many have made the switch to HPA only, so you may want to call before going to your local field with an empty Co2 tank in-hand.
HPA tanks can be refilled at paintball fields, airsoft fields, and some scuba shops. There may be other companies in your area that have compressed air and the proper equipment to refill an HPA tank, but you’ll have to search “fill HPA tanks near me” to find out.
How Much Does It Cost to Refill Co2 and HPA?
It costs (on average) $3 to $6 to fill up a Co2 tank and between $1 – $3 per 1000 PSI to fill up an HPA tank. Most paintball fields will only charge $1 per 1000 PSI, but other specialty shops may charge more.
How to Fill Co2 and HPA Tanks At Home
Is there nowhere to go in your area to fill up a Co2 or HPA tank? Or maybe you just want to be able to fill up your tank without having to go to your local field, scuba shop, or sporting goods store? If either is true, then fortunately there are ways to fill up a Co2 or HPA tank at home if you have the means to do so.
But be warned – being able to refill your Co2 or HPA tank at home isn’t going to be cheap, nor will it be completely safe (as long as you properly follow instructions you’ll be okay), but it is possible. Here’s how you can do it.
To fill up a Co2 tank at home, you’re going to need a 20 – 50 lb. steel or aluminum Co2 tank, a Co2 fill station, a digital scale, and a crescent wrench. You’re also going to need to get your large steel or aluminum Co2 tank filled at a gas supply store in your area. Or you can just buy a used tank from a local company for around $50 – $75 and exchange it for around $20 – $30 whenever you need it refilled.
I recommend the tank exchange as it will save you from having to buy a brand new 20 – 50 lb. Co2 tank and then having to get it hydro tested every 5 years. Now if you do want your very own bulk Co2 tank then I would recommend buying this one here on Amazon.com.
Once you have your bulk Co2 tank filled and ready to go, then you’ll need to connect your fill station to the large Co2 tank with a nylon washer in between each connector. Connect the fill station as much as you can by hand, then use your crescent wrench and tighten it the rest of the way. Once fully tightened, set up the digital scale on a sturdy platform and you’re ready to fill your Co2 tank.
Bonus Tip: Make sure to set up the digital scale on a sturdy platform to ensure the tank is properly weighed.
How to Fill a Co2 Tank With a Scuba Tank
- Make sure the fill and exhaust valves (rubber arms) are both set to the off position.
- Disengage the pin valve on the UFA (Universal Fill Adaptor). Loosen the knob all the way.
- Screw the paintball Co2 tank into the UFA.
- Rotate the knob on the UFA until the pin valve is engaged and then rotate it slightly more.
- Open the main valve on the bulk Co2 tank.
- Open the fill valve for 1-2 seconds to chill the tank.
- Open the exhaust valve until the rest of the Co2 is purged from the tank. The tank should be cold to the touch at this point.
- Turn the scale on, hang the paintball Co2 tank on the scale, zero the scale out.
- While the tank is still cold, open the exhaust valve until the scale reads (right under) 20 oz.
- Remove the Co2 tank from the scale and then rotate the knob on the UFA to disengage the pin valve.
- Once disengaged, purge the rest of the Co2 from the line by opening the exhaust valve.
- Unscrew the Co2 tank from the UFA and you’re ready to play!
You may have a different type of Co2 fill station than the type listed above, but they all work relatively the same way. You either have two valves (an exhaust and a fill valve) or one valve that functions for both exhaust and fill.
Trying to fill an HPA tank at home instead?
Unlike Co2, there are a variety of different ways to fill an HPA tank at home. You can either refill an HPA tank with a scuba tank, a regular compressor & booster compressor, a 4500-PSI air compressor, a hand pump, or an industrial compressor like the kind used at paintball and airsoft fields.
The best method for the money would be to buy a scuba tank and a scuba fill station such as this Ninja Fill Station on Amazon.com. Or you can spend a little bit more and buy an inexpensive air compressor rated at 4500 PSI such as the Yong Heng on Amazon.com.
Filling your compressed air tank with a hand pump would be even cheaper, but it can take hours to fill a simple 4500-PSI tank.
How to Fill an HPA Tank With a Scuba Tank
- Unscrew the knob on the HPA fill station until it can be attached to the scuba tank.
- Connect the HPA fill station to the filler adapter on top of the scuba tank.
- Rotate the knob on the fill station until the pointed end screws (all the way) into the indention end of the filler station.
- Make sure the bleed valve on the fill station is closed.
- Pull back the collar on the quick disconnect adapter on the fill station.
- Insert the fill-nipple on the HPA tank into the quick disconnect adapter on the fill station and push the collar forward.
- Slowly rotate the primary valve (black rubber knob on top of scuba tank) to fill up your HPA tank.
Using a scuba tank and a scuba fill station is the most cost-effective way to fill an HPA tank at home. A brand-new scuba tank will only cost around $180 (if you buy used pay attention to hydro test date) and a scuba fill station with a fill whip included can range anywhere from $30 – $80. Filling an 80 CF scuba tank with compressed air at your local dive shop can cost you anywhere from $8 – $10 and will provide you with 20+ fills for a 48, 68, or 72/4500 HPA tank.
However, an 80/3000 PSI scuba tank can only be filled up to 2750 +/- PSI on the first fill, with each subsequent fill being slightly less until the scuba tank runs completely out of air. If you want a scuba tank that holds more compressed air and will deliver more tank-fills then you’ll have to buy a larger-sized scuba tank that’s rated at a higher PSI.
Check out this HPA Tank Fill Calculator to get an idea of how many tank-fills you can get from a scuba tank.
Hydro Test: A water-based test that’s required every 5-years (15-year total) to ensure the structural integrity of the tank.
How to Fill an HPA Tank With a (4500-PSI) Air Compressor
Quick Warning: No two air compressors are exactly alike, so make sure to look at the owner’s manual (or search for it online) to find out the exact instructions and requirements of the air compressor you’re using.
The instructions below are a rough outline of how to use the Air Venturi 4500 PSI Air Compressor. Look at the owner’s manual for exact specifications.
- Connect the compressor to an electrical outlet.
- Close the pressure release valve on the compressor.
- Pour the required amount of oil into the oil pan.
- Pour the required amount of distilled water into the water tank.
- Set the shut-off pressure to the maximum pressure (3000 or 4500 PSI) of your HPA tank.
- Pull back the collar of the quick-disconnect on the end of the fill-whip.
- Insert the fill nipple of the HPA tank into the quick-disconnect and push the collar forward until it locks in place.
- Check the coolant levels and turn the Cooling System switch “ON”.
- Once the cooling system is running for 2-3 minutes, turn the Compressor switch “ON”.
- When the HPA tank reaches the desired amount of air, turn the compressor switch “OFF”.
- Open the pressure release valve.
- Once the pressure is released, disconnect the HPA tank from the fill-whip by pulling back the collar on the quick-disconnect.
- Turn the Cooling System switch “OFF”.
If you want to fill HPA tanks on your own without having to constantly visit a scuba shop then investing in an air compressor such as the Yong Heng or Air Venturi would be your best option. The Yong Heng is by far the more affordable option, but the Air Venturi is better in terms of performance and design.
How to Fill an HPA Tank With a Hand Pump
- Close the pressure relief valve near the bottom of the hand pump.
- Pull back the collar of the quick-disconnect on the end of the fill-whip.
- Insert the fill nipple of the HPA tank into the quick-disconnect and push the collar forward until it locks in place.
- Pull the hand pump up and push it back down repetitively until you reach the desired amount of pressure in your tank.
- Open the pressure relief valve until all of the air is released.
- Disconnect the HPA tank from the fill-whip by pulling back the collar on the quick-disconnect.
Using a hand pump is a great option for filling smaller-sized HPA tanks such as the 10, 13, or 26/3000 sized tank. A hand pump is also a great option if you’re only interested in plinking targets in your backyard.
For playing actual games, however, a hand pump simply isn’t going to provide you enough air for all-day play, even if you constantly pump the hand pump in-between games. Now if you only play stock class and take long breaks in-between games then maybe a hand pump will be enough to get you through the day, but then again maybe not.
Now if you don’t mind pumping a hand pump for hours at a time, and are fine with only playing until you run out of air, then the hand pump may just be the best option for your money. Of course, if the persons you’re playing with have to air up their HPA tanks with your hand pump as well, then you may want to save up your money and invest in an air compressor such as the Yong Heng.
Can You Fill an HPA Tank With an Air Compressor?
While you can’t fill an HPA tank with a regular air compressor by itself, you can invest in a booster compressor that connects to your regular air compressor to allow you to fill up to 3000 PSI.
The reason a regular air compressor (the kind used for pumping air into tires) isn’t capable of filling an HPA tank is because the maximum output pressure of an air compressor is typically around 150 PSI. This low of an output pressure isn’t even high enough to allow for a single shot from a low-pressure HPA tank rated at 400 PSI.
However, even though it’s possible to fill an HPA tank by connecting a booster compressor to your regular air compressor, I wouldn’t recommend it. In my opinion, you’re better off investing in an air compressor such as the Yong Heng and saving yourself both time and money. The Yong Heng air compressor is rated at 4500 PSI and will be able to fill your compressed air tank in minutes instead of hours.
What Is a Co2 Tank Exchange Program?
Some sporting good stores such as Dicks Sporting Goods will exchange your empty Co2 tank for an already filled Co2 tank of their own. Wal-mart used to have a Co2 tank exchange program back in the day as well, but it seems that Wal-mart no longer exchanges Co2 tanks anymore, but maybe your area is different.
What Is the Best Size Co2 Tank?
The best size Co2 tank for paintball is 20 oz, although the 24 oz is typically preferred by bigger-sized players. You can also buy Co2 tanks in the following sizes: 4 oz, 9 oz, 12 oz, and 16 oz.
Co2 even comes in disposable cartridges that are pre-filled in small 12-gram or 90-gram steel canisters. These miniature Co2 cartridges are typically used for stock class (pump) paintball guns and paintball pistols.
What Is the Best Size HPA Tank?
The best size HPA tank for the average adult player is the 68/4500 or 48/3000 sized tank. For younger players or players with short limbs, the 35/3000 or 48/4500 may be better suited for your proportions. On the other hand, if you’re well over 6-foot tall with long limbs then the 62/3000 or 77/4500 may be your best option.
Types of HPA Tanks
There are two main types of HPA tanks: tanks that hold up to 3000 PSI and tanks that hold up to 4500 PSI (Pounds per Square Inch). Since an HPA tank rated at 4500 PSI can hold 50% more pressure than an HPA tank rated at 3000 PSI (½ of 3000 = 1500 | 1500 + 3000 = 4500 | 1500 = 50%), a 4500 PSI tank can also hold 50% more shots. Therefore if a 68/3000 sized tank can hold up to 700 shots per fill, a 68/4500 sized tank can hold up to 1050 shots per fill.
Another difference between 3000-PSI tanks and 4500-PSI tanks is that 3000-PSI tanks are made from aluminum and 4500-PSI tanks are made from carbon fiber. Carbon fiber is a lighter material than aluminum, so even though 4500-PSI tanks hold more air than 3000-PSI tanks, they’re still lighter in weight. The only downside of owning a 4500-PSI tank is that they’re much more expensive, typically ranging anywhere from $150 – $230 depending on how it was made, where it was made (U.S.A vs Mexico vs an igloo in Canada), and what kind of regulator it has.
Read More: Best Compressed Air Tanks for Paintball
There are low-pressure regulators (400 PSI), high-pressure regulators (800 PSI), adjustable regulators (400 – 800 PSI), adjustable low-pressure regulators (150 PSI – 400 PSI), and adjustable high-pressure regulators (900 – 1200 PSI).
If you do plan on buying a compressed air tank then make sure the tank you’re buying has the correct regulator to match your paintball gun. Most high-end electro’s tend to operate on low pressure air, whereas most blowback markers such as the Tippmann 98 Custom, A5, Stormer, etc. operate on high-pressure air. Always do your research beforehand to make sure the regulator on the HPA tank you’re buying matches your paintball gun.
HPA Tank Sizes
The size of an HPA tank is measured by two factors: the size of the interior of the tank measured in cubic inches (CI) and the pressure capacity (3000-PSI or 4500-PSI) of the tank. This is why HPA tanks are listed as either **/3000 or **/4500. The ** is the two-digit number indicating the interior size of the HPA tank in cubic inches and the 3000 or 4500 listed afterward is the pressure capacity.
So if you see an HPA tank that’s listed as 68/4500, it means that particular tank can hold a maximum pressure of 4500 PSI and the inside of the tank can hold 68 cubic inches of compressed air.
How Many Shots Can I Get From A..
3000-PSI HPA Tank
4500-PSI HPA Tank
Best Places to Buy Co2 and HPA Tanks
There are many great paintball retailers online, but my personal favorites are Amazon.com, Ansgear.com, and HustlePaintball.com.
Do HPA and Co2 Tanks Expire?
The only type of Co2 or HPA tank that has an expiration date is HPA tanks rated at 4500 PSI. These carbon fiber compressed-air tanks expire only 15 years after being created and have to be hydro-tested every 5 years to ensure that the tank is still safe for use. All Co2 and HPA tanks made from aluminum have no expiration date, but they do all require hydro-testing every 5 years to ensure safety. Any Co2 or HPA tank that has an external diameter of two inches or less, and is less than two feet long, requires no hydrotesting.
How to Tell When Your Co2 or HPA Tank Should Be Hydrotested
Listed on the top of all Co2 and HPA tanks are a series of numbers, letters, and symbols. Somewhere amongst all those numbers, letters, and symbols is a set of two numbers, a symbol or letter, and then two more numbers, known as the “Born On” date. The Born On date is the date the Co2 or HPA tank was created and will look something like this: 01 © 21 (which means the tank was created on July 1st, 2021). Exactly five years after this date (July 1st, 2026) the tank will have to be hydro-tested.
How Much Does it Cost to Hydrotest a Co2 or HPA Tank?
The average cost to hydro-test a Co2 or compressed air tank is $30. For this price, you would be better off buying a new Co2 tank every time your current Co2 tank requires hydro-testing. HPA tanks, on the other hand, are probably worth the cost of hydro-testing, especially if you own a carbon fiber 4500-PSI tank. Now if your regulator is worn down and you own an aluminum 3000-PSI HPA tank, then you may just want to skip the hydro-testing and invest in a new tank altogether.