Interested in a cost savy solution for good "sparkling"/"bubbled"/"gazeified" water (a.k.a. "soda" water) at home? Not interested in encouraging large corporations nor questionnable business practices ? Here is a simple DIY solution using an elegant siphon bottle and a large CO2 tank, following these 3 easy steps:

All parts can be easily ordered online (at least in Canada) or even bought at your local hardware store (here at Home Depot).

Here is the bill of materials with indicative prices paid in Summer 2020:

• Component / Provider / Unit Cost / Tax / Shipping cost / Total cost (CAN$)
• Lead-in Hose / www.homedepot.ca / $23.47 / $3.52 / $26.99
• Quick connect A / www.homedepot.ca / $6.77 / $1.02 / $7.79
• Quick connect B / www.homedepot.ca /$8.74 / $1.31 / $10.05
• 1/4’’ NPT / www.homedepot.ca / $5.38 / $0.81 / $6.19
• Valve / www.homedepot.ca /$14.94 / $2.24 / $17.18
• Alumnium Tank 5 lb / www.ontariobeerkegs.com / $89.49 / $4.47 / $10.65 / $104.61
• Regulator / www.ontariobeerkegs.com /$94.99 /$4.75 /$8.02 /$107.76
• Soda Siphon / www.icotrading.ca / $42.99 / $2.70 / $0.00 /$45.69
• Metal Charger / www.icotrading.ca / $10.99 /$10.99

The total summed up to CAN$337.25, which is not cheap, but will be very quickly recovered, as explained in the ROI analysis in section 3.3 below.

Pictures of all parts are available, for the ones bought at my local Home Depot, the ones ordered at Ontario Beer Kegs and the ones ordered at Impeccable Culinary Objects.

The assembled system looks like this:

1. Wash all parts (excluding the regulator and CO2 tank) with hot water and soap and let them dry.
2. Drill a hole through the center of the distal end of the Metal Charger and tap it with a 1/4" NPT thread, then mount the female Quick Connect using the double-sided connector (see picture of the Quick Connect and the 1/4" NTP male connnector mounted on the Metal Charger).
3. Remove the existing 1/4" male flare outlet from the Regulator and replace it with the Valve connected to the Lead-in Hose (see picture of the regulator-valve-hose assembly)
4. Mount and tighly screw together all parts using teflon tape (see picture of all parts properly positionned before assembly). NOTE: This picture was taken with the existing 1/4" male flare outlet from the Regulator (removed in Step #3). This picture was also taken with the original black plastic charger provided with the Soda Siphon; it won't be used (as we will use the Metal Charger as detailed in Step #2) and can be saved for possible use with small 8g CO2 cartriges (for when you are on the road away from your 5 lb CO2 tank).

The 5 lb CO2 tank is typically pressurized around 1000 PSI with the regulated pressure can be adjusted between 0 to 160 PSI thanks to the Regulator, by turning the adjustement knob. A regulated pressure around 80 PSI should gives great bubbles and is perfectly safe** for the Soda Siphon bottle.

1. Pour 1 L of filtered (idealy) tap water into the Soda Siphon bottle (this ICO bottle comes with a spout tube at the entrance that automatically limits the volume to 1 L by entrapping a residual volume of air).
2. Place in the fridge for a couple of hours to maximise CO2 absorption.
3. Connect the quick-connect, then open the Valve, then open the CO2 Tank by turning the knob counter-clockwise (the primary pressure should be around 1000 PSI) and fill with CO2 until the regulator stops its squealing sound (the secondary pressure should be around 80 PSI).
4. Turn off the CO2 Tank by turning the knob clockwise and shake the Soda Siphon bottle until primary pressure drop to zero (should take less than 30 seconds if water is cold and shake is powerfull).
5. Close the valve and shake again for another 30 seconds (the secondary pressure should now be down to 60 PSI and won't drop, as the valve is downwards the pressure line): this ensures that all pressure from the Lead-in Hose is gone down the Soda Siphon bottle.
6. Disconnect the Quick-connect.
7. Enjoy and repeat.

According to my basic calculations (detailed in this graph and spreadsheet), the return on investment (ROI) is completed after 280 liters when compared to -cheap- bottled soda water and after 590 liters when compared to a mid-entry commercial solution. With our familly consumption, this correponds to respectively 1 and 2 years, for a device that will last much much longer and will minimize garbage or maintenance in the meantime. More math needed, really? NOTE: A full recharge of the 5 lb costs me $25+tx at a local microbrewery store and typically last between 9 and 13 months.

**NOTE2:The rating of the 18-8 stainless steel soda bottle I bought in Tokyo (Japan) in summer 2018 are the following ones: Internal pressure during use : 1.4 MPa (~200 PSI); Safety valve release pressure: 2.0-2.5 MPa (~290-350 PSI); Maximum pressure: 4.0 MPa (~580 PSI)