The electrolyzed, energized and ionized waters do not maintain their special properties indefinitely. This drinking water is most effective drunk fresh from the unit, but remains effective from the initial pour up to 48 hours later. 2.5 and 11.5 pH waters last longer, up to 2 weeks. Please check the 2.5 pH water by smelling it; if it smells like chlorine, it is still effective. You can check the 11.5 pH water by using it to emulsify sesame oil; if it emulsifies the oil, it is still effective. Time, heat, light, movement, and oxygen degrade the properties of these waters. For maximum shelf life, please store this water in a fully sealed dark container and minimize movement.