Before beginning, press on the lever to make sure that there isn't sparkling water already in the bottle. You don't want to add more gas to water that has already been carbonated.
Filling the bottle with water
Open the bottle by screwing off the top portion. Then, remove the tube in the center of the bottle.
Fill the bottle with cold water. When the water starts to come out of the top of the bottle, stop filling. If and when the water level falls, do not add more water. Most siphons are made to prevent overfilling by spitting out the excess water as you fill the bottle.
Add the tube back into the center of the siphon. Then screw the top of the siphon back on tightly.
Adding the gas
Remove the decorative cover on the head of the syphon, opposite the spout, by unscrewing it. This is where you will screw on the gas charger.
Place a gas charger into the holder with the tip facing outwards. Screw the holder onto the lid of the syphon. Doing so will pierce the tip, releasing the gas. (You should hear the sound of the gas being released.)
Give the bottle several shakes (at least 6) to help dissolve the gas into the water.
Remove the charger by unscrewing the holder. (Again, it's normal to hear a sound as you remove it.)
Screw the decorative cap back on.
Serve the soda water
Place an empty glass under the spout.
You can now serve the water by pressing on the lever. Press gently at first as there may be quite a lot of pressure when you first dispense the water.
Cold water is best because warm water doesn't achieve the same level of carbonation.Use only one soda charger for each fill. Don't try to over carbonate.