Starting plants in soil is a low-cost and simple method to begin a hydroponic garden. Sow seeds indoors four to six weeks prior to the date you want to move them into the hydroponics system. Transplant the seedlings when they are 2 to 3 inches high and have grown their first set of true leaves. Use caution while removing soil and moving the plants to prevent damage to the root structure.
Assemble the hydroponics system according to the manufacturer's instructions prior to transplanting into the growing pots. Fill the water reservoir with water and add the correct amount of growth nutrients based on the package instructions for the volume of water.
Fill large bucket and a watering can with room temperature water. Cold water will shock the plants and stunt the growth.
Remove the plant seedlings from the growing container. Hold the stems at the base of the plant and grasp the root ball to prevent damage.
Roll the root ball in your hand to knock off excess clumps of soil. Use caution to prevent damage to the root ball. Remove as much soil in this manner as possible.
Dip the root ball into the large bucket of water while holding the stem close to the base of the plant. Gently move the root ball through the water while pulling soil off the root fibers. Be careful not to tear the roots.
Hold the plant over the bucket and gently rinse any remaining soil off with a watering can. Remove as much soil as possible, but note that some soil may remain if removing it will damage the roots.
Fill the bottom of a netted hydroponics container with a layer of hydroponics soil-less medium. Set the root ball into the container and gently spread the roots across the bottom. Fill the container with hydroponics medium to cover the roots and part of the stem so the plant stands upright.
Set the netted container into the hydroponics growing system according to the manufacturer's instructions. Verify that the water flows through the netted pot so the roots stay covered in water. Adjust the height of the container as needed.