Hydroponics replaces soil with nutrient-rich water so roots absorb food directly from liquid. This experiment compares three methods: a soil tray, a water culture system with an air pump, and a flood-and-drain system. The soil-grown radishes actually grew tallest, showing that water-based growing does not always outperform dirt.

Different growing media deliver nutrients to roots in different ways. Soil releases minerals slowly as water passes through it. A flood-and-drain system soaks the roots three times a day in nutrient solution. A water culture system uses an air pump bubbling nutrients around the roots nonstop. In one experiment, soil-grown radishes averaged 5.75 cm tall. The flood-and-drain group reached 3 cm, and the water culture group reached only 2.5 cm. The medium roots sit in shapes how well the plant takes up what it needs.