Hydroponic growing systems don't use soil, instead relying primarily on water, along with a growing medium, which can be sand, perlite (volcanic glass), gravel, coconut fiber or even air, among other things. Without soil, nutrients must reach plants through water. This requires special hydroponic fertilizer. Since plants don't need to search soil for nutrients, they tend to grow faster and, if the plants' other needs are met (appropriate light, for instance), they are more fruitful. The trade-off is that hydroponic gardening requires paying a lot of attention to the plants' needs.
Learn the needs of your plant, including pH, light and the temperature your plant needs.
Prepare the starter cubes, if necessary, according to package directions.
Poke a hole in the cube up to one-half inch deep and add seed.
Cover the seed with some of the cube material.
Wet cube as needed to keep it moist.
Mix a nutrient solution from water and hydroponic fertilizer according to package directions.
Test the pH of the solution.
Adjust the solution according to the needs of your plant.
Wet the cube using one-quarter to one-half strength nutrient solution after the seeds have developed true leaves.
Choose the appropriate growing medium, according to your plant's needs and the hydroponic system you are using.
Add your chosen growing medium to the growing container of your hydroponic system unless your system is using air as the medium.
Plant seedlings in the growing medium after roots have emerged from the starter cube.
Water or mist the plant one to three times per day, depending on the system, or more if the plant demands it. If using a separate reservoir for the nutrient solution, keep the water level adequate.
Care When Using a Recycling System
Check the pH of the nutrient solution periodically if using a recycling reservoir hydroponic system. Adjust as necessary.
Flood the growing medium with clean water and drain it periodically: once every 10 to 14 days.
Mix a new nutrient solution, check pH, and adjust if necessary.
Add solution to the reservoir or the growing medium, whichever is appropriate for your system.