There is much dispute about whether club soda can actually replace seltzer water. Some people say that the two are virtually interchangeable, while others believe that there are some subtle differences between the two.  Here's what you need to know: Club soda is made by adding carbon dioxide to regular tap water. This gives the water a slightly fizzy taste and makes it somewhat more acidic.  On the other hand, Seltzer water is just regular water that has been carbonated using a machine. It's less acidic than club soda and typically has a stronger fizz. Yes. You can use club soda to replace seltzer water.