How to Make Carbonated Water
If you want to make carbonated water, fill a soda siphon or seltzer bottle with cold tap water. Put the CO2 canister in the cartridge holder and screw it into place. Press the plunger or button to dispense the entire CO2 canister into the water, then shake the bottle well to distribute the carbonation. Unscrew the CO2 holder and replace it with the cap, then refrigerate the bottle. If you'd like, you can add flavored syrups or juices to your carbonated water to flavor it!
Acquire a soda siphon or seltzer bottle and CO2 chargers that fit on the bottle. This system is a combination of a soda siphon and a CO 2 gas canister that carbonates the water. Buy one online or at a large kitchen department store. Most soda siphon systems hold 1-2 quarts (0.95-1.90 L) of water. Buy whichever size suits you, depending on how much carbonated water you want to make at a time. Keep in mind that many of the CO 2 chargers for these systems are single-use. Buy a pack of them big enough to last for a while. Modern soda siphons are the equivalent of seltzer bottles that have been around for about 100 years. Some antique shops or online auction sites may sell older seltzer bottles that still work. You will have to experiment with different sizes of CO 2 canisters if you buy and old-style seltzer bottle to find one that fits. Fill up the soda siphon or seltzer bottle with cold tap water. Take off the top of the soda siphon bottle and hold it under the tap until it is full. Screw the top back on securely and make sure it is not leaking. You can use filtered, chilled tap water if you prefer. It's not recommended to fill the soda siphon with anything other than water; however, you can easily flavor the water later after you carbonate it. Put the CO2 charger into the bottle’s spray head. Slide a fresh CO 2 canister in the cartridge holder and screw it into place.. Be careful as you attach the cartridge not to accidentally press the release for the CO 2 before you are ready to carbonate the water or you will waste the CO 2. Follow any manufacturer's instructions for attaching a new CO 2 canister to the siphon bottle, as some may have different mechanisms for securing it in place. Press the plunger or button to carbonate the water then shake the bottle. The plunger or button will release the gas into the water when you press it. Shake the bottle well to distribute the carbonation after all of the CO 2 is released into the water. Soda siphons will use up the whole CO 2 canisters that fit in them to perfectly carbonate the amount of liquid in them. You should empty CO 2 canisters before you dispose of them. If there is still some gas left in the cartridge, leave it in the soda siphon and press the button again to release all the gas. You can recycle the empty canisters. Unscrew the CO2 holder and replace it with the cap, then refrigerate the bottle. The soda siphon or seltzer bottle will have a cap to replace the CO 2 canister holder. Refrigerate the bottle for 3-5 hours before you use the water for the best carbonation. Serve your newly-carbonated water in a glass to drink right away, or pour it into other bottles and store it in the fridge for later use. Make sure not to leave much air space if you are storing it in bottles to preserve the carbonation. You can flavor your carbonated water by adding flavoring syrups or juice. Start with 4 US tbsp (59 mL) of flavoring syrup or juice and add more to taste. Homemade carbonated water will last for about 2-3 days in the fridge before it starts to go flat. Buy a home soda maker or sparkling water maker machine. There are several companies that offer these systems for carbonating water at home. They will come with a CO 2 canister and a carbonating bottle that fit in the system. Some systems also offer adapters so that you can attach them to other sizes or types of CO 2 canisters. If you drink a lot of sparkling water, these systems can help keep you from wasting so many plastic bottles, and even save you money depending on how much carbonated water you actually buy every year. Attach a new CO2 cartridge and the carbonating bottle full of water to the machine. Follow the manufacturer's instructions to attach the gas canister to the soda maker machine. Fill the carbonating bottle with cold tap water and either snap or screw it into place. Keep in mind that different machines use different types of CO 2 canisters. Some may be single-use that you need to replace every time, while others may use bigger refillable canisters. CO 2 is non-toxic, non-flammable, and the canisters could only explode with extreme changes in air pressure. You do not need to take any special precautions when handling the canisters. Press the carbonating button at least 3 times to carbonate the water. Soda maker machines allow you to control the level of fizz of your carbonated water. Experiment with the number of times you press the button to find the level that you prefer. Taste the carbonated water after you press the carbonating button 3 times. If you want more carbonation, you can reattach the bottle and press the button a few more times to inject more bubbles. Serve your carbonated water right away, take it with you on the go, or store it in the fridge for later. You can buy more carbonating bottles for your machine, or transfer the water to other bottles and store them in the fridge. Carbonated water from soda machines will stay good in the fridge for 2-3 days. You can flavor the water after you carbonate it with special flavoring syrups. Add 4 US tbsp (59 mL) per 16.9 oz (0.5 L) bottle of carbonated water. Add more to taste until you have a beverage you like. 
Acquire a soda siphon or seltzer bottle and CO2 chargers that fit on the bottle. Fill up the soda siphon or seltzer bottle with cold tap water. Put the CO2 charger into the bottle’s spray head. Press the plunger or button to carbonate the water then shake the bottle. Unscrew the CO2 holder and replace it with the cap, then refrigerate the bottle. Buy a home soda maker or sparkling water maker machine. Attach a new CO2 cartridge and the carbonating bottle full of water to the machine. Press the carbonating button at least 3 times to carbonate the water. 