What’s the difference between club soda, seltzer water and tonic water?

Are these identical-looking mixers interchangeable, or do they have properties that make them unique?

 While playing with drink recipes, I realized I didn’t know what the difference was between club soda, seltzer water and tonic water. Since I’ve always followed recipes when mixing drinks, I just bought what the recipe called for. I realize I probably should have known the difference, given my love of food and drink, but I didn’t. So, I set out to find out what is in each mixer and if they’re interchangeable with each other. They all look the same. Can they all be used the same way?

Club soda

Club soda is carbonated water that has added minerals like potassium bicarbonate and potassium citrate to enhance the flavor. It can also have added sodium, but not all club sodas contain sodium.

Seltzer water

Seltzer water is also carbonated water, but it doesn’t have any additives, including sodium. You can purchase flavored seltzers, usually in a citrus flavor, but plain seltzer is simply water that is carbonated.

Tonic water

Tonic water is the least water-y of the three. It does contain carbonated water, but it has quinine to give it a bitter flavor and also a sweetener, usually high fructose corn syrup or an artificial sweetener to make a “diet” tonic water. It’s more of a soda than a water.

Club soda and seltzer water are interchangeable in beverages, but tonic water will add both sweet and bitter to whatever you’re creating. You shouldn’t substitute tonic water for club soda or seltzer water nor should you substitute club soda or seltzer water for tonic water.