Normally, the plant should be transplanted into the hydroton with their root wasted off the dirt. There is also another way to use this. The pots bought in the market can be put directly on top of the hydroton with the holes in the bottom touching the water. The nutrient water gets wicked up in the soil and keep the soil moist. With enough nutrient delivered this way, the plants grow happily without the need to replot the plants into bigger pots. The plan also gets water automatically from the bottom. There is no need to water them.