We’d been using Sodastream for a few years and were a bit tired of the cost and the hassle of getting new bottles delivered. While, for the vast majority of users, Sodastream is great, it just wasn’t for us. But how could we get inexpensive carbonated water?

We build a home carbonator system that cost us about $120 in parts and costs about $15 in refills every six months or so. What’s the biggest difference between my system and Sodastreams? Sodastream uses smaller 33-ounce tanks – good for 150 charges – while I bought a five pound tank at the local welding shop (or you can pick up this 5-pounder here for $69). The 5 pound tank should be good for almost 500 if not more, depending on how bubbly you like your water. In many other ways, in fact, the Sodastream is a nicer kitchen appliance and looks much better than a huge CO2 tank on the kitchen counter. The 5lb solution, however, is far more cost-effective.

What You Need
1. A 5lb tank (or larger, if you have the space). Fill it with CO2. This works fine or you can get a used one at your local welding supply.


5/16″ Gas Line Assembly – Ball Lock


The Carbonater

4. Gasket tape. You may have this lying around the house and you won’t need very much.


Kegco Premium Pro Series Dual Gauge Co2 Draft Beer Regulator. This regulates the flow of CO2 into your bottle.

Building It
1. Ensure the canister valve is closed tightly. You may also want to assemble your kit outside. This is a high-pressure tank, so try to be a bit cautious.

2. Wrap a small length of gasket tape around the threads of the CO2 bottle. Hand tighten the regulator (the device with two dials) to the CO2 tank. Don’t over tighten and ensure that the tape isn’t bunching up on the threads.

The Carbonater and Ball Lock

3. Attach the host and ball lock assembly to the regulator’s gas output. The output looks like a serrated Christmas tree. Push the unconnected end of the hose up the serrated part and then attach the small clamp included in the package.
4. Stick the Carbonater cap into the ball lock. This completes the kit.
5. Ensure the regulator is closed (the little blue handle is “down” rather than aiming along the hose) and turn the valve on the CO2 tank, releasing the gas. You can now test the assembly by turning the regulator handle. If you have the Carbonater cap attached, gas will escape.

Filling Your Bottles

1. Grab a 2-liter bottle (preferably one used for seltzer and not flavored soda) and fill up to about three inches from the top.

2. Squeeze the top of the bottle so the water level goes almost to the top.

3. Attach the Carbonater top and then connect the ball lock assembly by pushing it down onto the Carbonater.

4. Unleash the gas. The bottle will expand and gas will flow into the water. Shake the bottle for a few seconds – I like to hit about 20 seconds but you can shake for a minute of you’re looking for a solid fizz.

5. Modify the regulator (if necessary) to improve the pressure. You will be cautious the first few times but don’t give up. Eventually you’ll figure out the right pressure level and shaking time. Carbonation is an art.

Mounting the kit

I have our kit under the sink in the kitchen. I ran the hose using 3D printed hooks that I embedded right into the wood – you can use something like this if you have a 3D printer or a simple hook if you don’t. To make the seltzer I pull the hose off the hooks, attach everything, and turn the switch. A few seconds later and I’ve got my bubbly.