Plants absorb moisture and nutrients from the soil. Moisture crystals ensure that an even distribution of moisture remains constant in your soil. As your potting soil dries, the moisture and nutrients stored in the crystals is released into the soil to be used by the plant. Each time you water your plants the moisture crystals reabsorb water and store it for later use when the soil is dry. The moisture crystals actually capture and store the water that normally drains away. It’s a slow and steady release of water keeping your plants happy and healthy.