Lessons on Hydroponics

Tomatoes can be grown hydroponically.

Growing plants in water instead of soil is a process known as hydroponics. Understanding the classifications of hydroponic systems will help you choose the type of system to start with for your own hydroponic garden. Some of the essential techniques used in maintaining a successful hydroponic system include using growing mediums for aeration, adding nutrient solutions for fertilizing, and maintaining pH levels.

Hydroponic Systems

Hydroponic systems are classified in two ways, as active or passive. In an active system, you can use pumps to move nutrient solutions. In a passive system, a growing medium or a wick absorbs the nutrient solution and then passes it to the root system. Active systems supply more oxygen to the root system than passive, thus improving rates of growth. Some hydroponic system techniques include the static aerated technique (SAT), ebb and flow technique (EFT), deep flow technique (DFT), drip irrigation technique (DIT) and root mist technique (RMT).

Growing Mediums

You can use growing mediums to anchor and aerate root systems. Growing mediums direct the water and nutrients to the roots. There are many types of growing mediums, each medium being used for a different hydroponic system, including hydrocorn, baypor, and rockwool. Hydrocorn is a long-lasting, clay rock medium that provides plenty of oxygen to the root system in an ebb and flow system. Baypor is a lava rock medium that is reusable in an ebb and flow system, but is not as long lasting as hydrocorn. Rockwool is a volcanic rock and limestone medium that is used in any hydroponic system.

Nutrients

Nutrients are fertilizers for hydroponics that you can use to replace all of the nutrients that you find in soil. Plants require twenty mineral elements, six macro nutrients and nine micro nutrients, so nutrient solutions are necessary for a plant's health. Nutrients come in liquid and powders, and are available in both chemical and organic forms. Although organic forms of nutrients may be preferred, they require more work to maintain your hydroponic system, because the compounds break down and can block the system.

pH

Maintaining a proper pH level in your hydroponic system is important for the healthy growth of your plants. An average pH level ranges between 5.5 and 6.8 for most plants. You can test your pH levels by using pH testing kits that are available at hydroponic supply, pet and hardware stores. These pH test kits come in paper test strips, liquid, and the more expensive high-tech digital meters. To raise a low pH level, soluble potash is used. To lower a high pH level, phosphoric acid is used.

References

• Aquamist: Hydroponic Methods
• Simply Hydroponics and Organics: Growing Medium
• TPS.com: Hydroponic Nutrients
• Simply Hydroponics and Organics: pH

Resources

• Hydroponics B.C.: Hydroponic Gardening for Beginners
• How-To Hydroponics: Hydroponic System Plans & Hydroponic Gardening Guide