Ebb and Flow grow systems pump a water and nutrients solution into your root zone for a specified time to allow for absorption into the roots and up into your plants. After the plants get enough water, the pump drains the water and nutrient solution back into a reservoir until the next set time for the ebb and flow. Growing mediums such as coco fibers, perlite, expanded clay pebbles, and more can be used in an ebb and flow system for the roots to attach onto and support your plants.