How can I properly store lettuce in water to keep it fresh for a longer period of time?

To properly store lettuce in water and keep it fresh for a longer time, place the lettuce in a container with water, making sure the leaves are submerged but not packed tightly. Change the water every 1-2 days and store the container in the refrigerator. This will help maintain the crispness and freshness of the lettuce for a longer period.