Water ionizers are devices that use electrolysis to separate water into alkaline and acidic components. They typically connect to a kitchen faucet and filter tap water before passing it through electrodes. The result is alkaline water, which is believed by some to have health benefits, such as improved hydration and antioxidant properties. The acidic water produced can be used for cleaning and disinfecting. While proponents claim various health advantages, scientific evidence supporting these claims is limited. It's important for consumers to research and consider the potential benefits and drawbacks of using a water ionizer before making a purchase.