One of the benefits of having a keezer is that it can also be used to serve non-alcoholic beverages. The first drink I served from the keezer was actually seltzer since it’s so cheap and easy to make. You just fill a keg with water and let it carbonate. My first keg I used the shake method to force carb it, but decided I wanted something a little faster and less manually involved. I ordered a force carbonation lid with diffusion stone. Instead of pumping gas into the top of the keg, the gas is pushed through a diffusion stone in the bottom of the keg. The stone has 0.5 micon holes in it that helps to create millions of tiny bubbles that increase the surface area of the gas/water interaction. This helps the gas dissolve faster. Some people use the lid to carbonate quickly and then replace it with the standard keg lid. I just leave mine hooked up all of the time though.