Home & Garden Home What's the Difference Between Club Soda, Seltzer Water and Tonic Water? By Robin Shreeves Robin Shreeves Writer Cairn University Rowan University Wine School of Philadelphia Robin Shreeves is a freelance writer who focuses on sustainability, wine, travel, food, parenting, and spirituality. Learn about our editorial process Updated May 14, 2020 Club soda on the rocks ... or is it?. (Photo: Marco Verch Pro [CC by 2.0]/Flickr) Share Twitter Pinterest Email Home Sustainable Eating Pest Control Natural Cleaning DIY Family Green Living Thrift & Minimalism My recent obsession has been beverages. It all started with limoncello. Now, I’m creating cocktails at home and ordering unusual cocktails when I'm out. I’m buying shrubs and making my own. I’m also diving into many styles of beers that I’ve never tried before and hounding my beer-brewing friends to let me try everything they make. 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 know the difference, given my love of food and drink. So, I set out to find out what is in each mixer and if they’re interchangeable. 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, such as 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. There you have it — a simple explanation about these three common drink mixers. Did you already know this, or did I teach you something?