How to Refill SodaStream at Home Using a CO₂ Tank
If you use a SodaStream regularly, you’ve probably noticed how quickly the small cylinders run out—and how expensive swaps can become over time. That’s why many people are turning to DIY SodaStream refill setups using larger CO₂ cylinders.
With the right equipment, a 5 lb, 10 lb, 15 lb, or 20 lb CO₂ tank can refill multiple SodaStream cylinders at a fraction of the cost. But it’s important to set things up properly to ensure safety, efficiency, and compatibility.
This guide breaks down how to do it, what equipment you need, and how to keep your CO₂ supply running reliably at home.
Why Use a Larger CO₂ Cylinder for SodaStream?
A standard SodaStream cylinder contains about 14.5 oz of CO₂. By comparison:
A 5 lb tank can refill ~6–8 SodaStream cylinders
A 10 lb tank can refill ~12–16 cylinders
A 20 lb tank can refill 25+ cylinders
This dramatically reduces cost per refill and eliminates frequent trips for exchanges.
Required Equipment for a Home Refill Setup
To safely refill SodaStream cylinders from a larger CO₂ tank, you’ll need the following:
1. CO₂ Cylinder (CGA320 Valve)
This is your main supply tank. Most setups use:
5 lb for compact home use
10–20 lb for higher volume or long-term savings
All cylinders in Canada must be hydro tested every 5 years. If your tank is out of date, it cannot legally be refilled.
2. SodaStream Refill Adapter Kit (CGA320 to TR21-4)
This is the key component that connects your large tank to your SodaStream cylinder.
Look for:
“Soda Refill Bottle CO₂ Adapter Refills Connector Kit (CGA320 to TR21-4)”
This adapter:
Threads onto your main tank (CGA320 fitting)
Connects directly to SodaStream cylinders (TR21-4 thread)
Allows controlled transfer of CO₂
Make sure the adapter includes:
A bleed valve (for safe disconnect)
High-pressure rated fittings
Solid metal construction (avoid cheap plastic components)
3. Precision Scale
Weighing cylinders during refill is critical. Overfilling can be dangerous.
Always fill by weight, not pressure
A standard SodaStream cylinder should not exceed ~410g of CO₂
4. Freezer (Optional but Recommended)
Chilling the small cylinder before filling improves transfer efficiency. Cold cylinders accept CO₂ more easily.
5. Protective Gloves
CO₂ expands rapidly during transfer and can cause frostbite. Always wear gloves when handling cylinders during filling.
Step-by-Step: How the Refill Process Works
Chill the empty SodaStream cylinder (optional but recommended)
Attach the adapter to the main CO₂ tank
Screw the SodaStream cylinder into the adapter
Slowly open the main tank valve
Allow CO₂ to transfer (typically 30–60 seconds)
Close the valve
Use the bleed valve to release pressure
Remove and weigh the cylinder
Always stop filling if:
You hear irregular flow
Frost builds excessively
Weight exceeds safe limits
Safety Considerations
CO₂ is safe when handled correctly, but improper use can create risks.
Follow these guidelines:
Always store cylinders upright and secured
Never overfill SodaStream cylinders
Only use equipment rated for high-pressure CO₂
Keep tanks away from heat sources
Ensure good ventilation in enclosed spaces
For a breakdown of cylinder safety and testing requirements, see:
https://tc.canada.ca/en/dangerous-goods/cylinder-requalification-facilities
Refilling and Hydro Testing CO₂ Tanks in Ottawa
Even with a home refill setup, your main CO₂ tank still needs:
Regular refills
Hydro testing every 5 years
Visual inspection for safety
At Rapid CO₂ in Ottawa, we provide:
CO₂ refills for 5 lb, 10 lb, 15 lb, and 20 lb cylinders
Hydro testing for expired tanks
Replacement cylinders if yours fails inspection
We supply CO₂ for:
SodaStream users
Home brewers
Aquariums
Draft systems
To book a refill or test, call 613-299-8412.
Other Ways to Use a CO₂ Cylinder at Home
Once you have a larger CO₂ tank, you can use it for more than just SodaStream refills:
Planted aquariums (CO₂ injection)
Carbonating cocktails or cold brew
Paintball or airsoft tanks
Sparkling water setups beyond SodaStream
A single cylinder can power multiple systems with the right adapters.
Final Thoughts
Setting up your own SodaStream refill station is one of the most cost-effective ways to use CO₂ at home. With the proper adapter, safe handling practices, and a certified cylinder, you can eliminate ongoing refill costs and always have carbonation ready.
The key is doing it safely—and keeping your main tank properly tested and filled.
