Yes, experience the hydration benefits of electrolyte-infused water in a UltraPress or GeoPress when equipped with a One-Way Electrolyte & Drink-Mix Valve (available since April 2023). Always add electrolytes into the clean drinking water side. Avoid adding flavoring or electrolytes directly into a cartridge not equipped with a One-Way Drink Mix Valve, as it can diminish the cartridge's lifespan and efficacy. In those situations, pour the clean drinking water into another water vessel and then add electrolytes or flavorings.