Schools, community groups, and individual consumers are exploring hydroponics as a way to have year-round, environmentally controlled plant production systems. This blog provides an introduction to hydroponics by explaining: advantages and disadvantages, and types of common systems. Readers will find recommendations for science, technology, engineering, and mathematics (STEM) inquiry activities aligned with hydroponic production systems.
At left is an image of a nutrient flow technique (NFT) hydroponic system with three types of lettuce ready for harvesting: Lettuce Leaf, Oakleaf: Lactuca sativa; Arugula: Eruca sativa; and Austrian Heirloom Romaine: Lechuga Forellenschluss.
What is hydroponics?
Growing plants hydroponically means that plants grow without soil, in a water-based nutrient solution, in materials that give plants the support they need to thrive in a growth chamber with a delivery system that gets the nutrient solution to the plant roots. A hydroponics plant production system will use either natural or artificial lighting.
Types of Hydroponic Systems
Passive systems use no energy to move nutrients and water to plant roots.1 There are four common types of hydroponic systems: passive, active, water culture, and media-based. Many science teachers are familiar with the wick-based system used in the Wisconsin Fast-Plants bottle biology plant growth system. An example of the Fast-Plants bottle biology system is shown at left. 
Active systems (like the NFT system shown at right) rely on energy, usually electricity via a pump, to move plant nutrients and water to and from the plant roots. Systems with pumps to aerate and deliver more oxygen to roots tend to produce healthier plants more quickly than passive systems.
Read more about hydroponic systems…
More information about hydroponic systems and images of different types of teacher-friendly systems is available in this presentation: Hydroponic Plant Production Systems: hydroponicsintrolfr-8nov2016-sm
1. KidsGardening.org↩