Classroom Hydroponics Project January 2022

Hydroponic Gardening - A STEAM Lesson

Seedlings Germinating
Water Reservoir Hydroponics
Hydroponics System 1

The Lesson: 

Our 2nd grade class has been learning about growing plants in a sustainable manner by using a hydroponics system.

Lessons have focused on What, Why, and How plants are grown in a hydroponic system.

This lesson is important as the Southwestern states in the United States have faced water rationing and other climate challenges.  Since hydroponic systems require a limited amount of water and no soil, hydroponics is a great solution for thirsty states like California, Nevada, Utah, among others.

      NEXT Generation Science Standards:

Ess2-1 – Compare multiple solutions designed to slow or prevent wind or water from changing the shape of the land.

Are you a parent or a teacher?  

Would you like to teach this lesson to your children or students?  If so scroll to the bottom of this page, I have listed everything that I used to teach this lesson.

What is Hydroponics? 

Hydroponics is simply the process of growing fruits and vegetables (and even flowers) in water or other mediums, but without any dirt or soil.  Other mediums include sand, coconut fiber, gravel, etc.  Without the use of soil, nutrients are added directly to water for plants to grow and mature. Hydroponics limits the amount of water used as much of the water is recycled within the system.

Why is Hydroponics Important? 

Hydroponics is not just important, but necessary in many situations.  In the midst of a drought, hydroponics can help grow crops to feed the population by limiting water usage as water is pumped and recycled.  Additional water is seldom necessary and only uses a fraction of what a normal garden uses.  In locations where sunlight is limited, hydroponics can be used to grow food, flowers, and all types of plants indoors without the natural sunshine.  Artificial lights can be directed towards the hydroponic system and assist in photosynthesis. In urban developments and urban dense areas, hydroponics can be used to vertically grown plants and food indoors and on rooftops without the need and the weight of soil.  Hydroponic solutions do not require inground irrigation systems that can change the shape and characters of the land. 

How Does Hydroponics Work? 

When setting up a hydroponic system one must consider the different types of hydroponic systems.  For the purpose of our assignment, the 2nd grade class used Ebb and flow systems.  This system required placing the plants over a grow bed with a water reservoir underneath.  A submersed pump is placed in a main water reservoir, where most of the water is held.  The pump acts as both a pump and a timer.  Every 15 minutes (or whatever the class has elected) the pump will activate and circulate water throughout the entire system and bring nutrient rich waters to the plants.  The Ebb and Flow System grows easily and faster than other hydroponic systems. This system can be set up manually without a pump.  If the manual option is chosen, nutrient rich water needs to be flooded into the water reservoir under the plants on a daily basis to ensure that plants get enough nutrients.

Other Frequently Asked Questions –

The water acts as a nutrient delivery medium.  In hydroponics, plant roots are submerged in the water, which allows the absorption of nutrients

How expensive is it to set up a hydroponic system?

Hydroponic systems require close monitoring and can be time consuming.  The learning curve can be steep when you first start. 

Hydroponic Farming does not require soil.  Thus, more plants can be grown in a smaller space, which can cut the cost of farming.  Hydroponics farms can be set up indoors, which allows for close control over the crops environment. Hydroponic systems can use less water than traditional farming methods. 

There are several types of hydroponic systems.  The most used are

  • Drip System
  • Ebb and Flow System
  • Nutrient Film Technique System
  • Deepwater Culture System
  • Wick System

Hydroponics is the cultivation of plants in nutrient rich water.  Aquaponics includes the use of fish (and waste) and bacteria as a means of nutrients for the plants.

Steps to Teaching this lesson

Step 1: Supplies – 

Many different hydroponic system choices can be found on Amazon.

You will need hydroponic fertilizer.

All totaled I spend just over $200 on this system (including fertilizer). If you get a smaller system, it will likely be less expensive.  I wanted one that could hold plants for all of my students. 

Workbook – I put together a workbook for the students to complete, while we discussed aspects of hydroponics gardening in class.  This workbook was complied using worksheets from Teacher Geek.

Step 2 – Engineering – Build the System – 

Building this system was fairly easy.  It involved simply pushing different PBC parts together. I did end up using a mallet to tap the various pieces more tightly together.  Depending on the age of your students that can help with this process. You will also notice that there is Hydroponic System Engineering Notebook that you can download on from Teacher Geek.

Step 3 – Science – Teach lessons about Hydroponics using the Hydroponic Worksheets with the class. We did this over the course of a couple of weeks while we also planted our seeds and setup the system. 

        NEXT Generation Science Standards: Ess2-1 – Compare multiple solutions designed to slow or prevent wind or water from changing the shape of the land.

Optional add lessons for Art, Math, and Technology to make this a lesson that hits all STEAM content areas.

Art – Our class drew a picture of a plant using Art For Kids Hub on YouTube

        California Art Standard: Va:Cn10: Create works of art about events in home, school, or community life.

Math – We made word problems based on the number of plants that lived (yes a few did not survive).

Technology – Students used Google Slides to make presentations on how hydroponic gardening works. 

        ISTE Technology Standard: 1.1.c – Students use technology to seek feedback that informs and improves their practice and to demonstrate their learning in a variety of ways.

Seed Planting and System Setup

To germinate the seed I place paper towels into a clear storage tub.  Then wet the paper towels.  Have students place seeds inside the container. Leave container near the window, or outside. Wait 10 days.  The seeds will sprout.

Have students take seedlings and place them into the foam squares that likely came with your hydroponic system (substrate may vary). These squares then get pushed into net pots.

Place net pots into your hydroponic system.  You will want to be sure that you have your system setup somewhere that will get sun, if you are not using grow lights. 

Make sure you have water in your systems reservoir.  Place the pump into the reservoir and hook it up. 

Plug the pump into the wall.

Put nutrients into the water.

My system didn’t come with a reservoir so I used a storage container.

I keep the HP System outside but power cord for the pump goes into a plug in the classroom.

Water Reservoir Hydroponics

Hydroponics System 1