Exploring Aquaponics

Categories: Easy Do-at-Home Activity , Agriculture , Plants

The students will identify the basic needs of plants and fish and engineer, assemble, maintain, and observe a small-scale aquaponics system that meets plant and fish needs.

Virtual lesson can be found here!

Activity 1: Introduction to Aquaponics (Day 1)
1. Ask the students, “Where is the food you eat grown?” After discussing the student responses, ask them if they think food can be grown in the middle of a big city.

2. Show the video Aquaponics – Pass the Plate.
   3. Ask the students why it might be beneficial to raise fish and plants together in one system. Use the following points to guide the discussion: The fish waste is not released into the environment.

• The waste produced by the fish is used as fertilizer for the plants.
• The plants purify the water for the fish.
• Food can be produced using less water than traditional growing methods. This allows food to be produced during droughts or in areas with little water.
• Fish and vegetables can be raised at the same time.
• Food can be produced in a small space and does not require fertile soil.
• Food can be grown in highly populated urban areas where fertile soil is scarce.
• Food can be produced indoors where weather and pests are less of a problem.
• No weeding is required.

4. Explain to the students that they are going to learn about the basic needs of plants and fish so that they will be prepared to care for them in a classroom aquaponics system that they will observe.Activity 2: Needs of a Plant (Day 2)
   Choose one of the following activities for students to complete either Growing Bracelets or Growing Beans in a Bag.
   
   Growing Bracelets Instructions:
   1. Ask the students if they have ever taken care of a plant. If they have, ask them to describe what they did to care for their plant.
   2. Today, we will be making a growing bracelet that represents the needs of a plant.
   3. Provide each student with a set of materials.
   4. Ask the students, “What are the basic needs of plants?” (nutrients, water, air, light and care) As students mention each need, instruct them to add the corresponding bead to their pipe cleaner or to their seed bag based on .
   Sun/Light – yellow bead – the source of heat and light on Earth and it sustains life on our planet.
   Nutrients – brown bead- these are the vitamins and minerals plants require for healthy growth and development and are transported by the roots. They come in the form of different substances such as fertilizers.
   Water – blue bead – is a clear, odorless and tasteless liquid. Water is essential for plants and animals to live. Living organisms are made up of mostly water – plants typically are 90+% water.
   Air – clear bead – is a colorless, odorless, tasteless gas. Air provides plants with life giving carbon dioxide. Plants “breathe in” the CO2 through their leaves and “breath out” oxygen.
   Plant – green bead – can represent a crop plant, tree, or anything they’d like to grow. Care – red bead – represents the care and nurturing on which plants thrive.
   
   Growing Beans in a Bag
   1. Ask the students if they have ever taken care of a plant. If they have, ask them to describe what they did to care for their plant.
   2. Today, we will be growing a seed using water beads that represent the needs of a plant.
   3. Provide each student with a set of materials.
   4. Instruct students to place their bean seed into the small provided bag.
   4. Ask the students, “What are the basic needs of plants?” (nutrients, water, air, light and care) As students mention each need, instruct them to add the corresponding water bead to their bag with the seed to represent that need.
   Sun/Light – yellow water bead – the source of heat and light on Earth and it sustains life on our planet.
   Nutrients – light blue water bead- these are the vitamins and minerals plants require for healthy growth and development and are transported by the roots. They come in the form of different substances such as fertilizers.
   Water – dark blue water bead – is a clear, odorless and tasteless liquid. Water is essential for plants and animals to live. Living organisms are made up of mostly water – plants typically are 90+% water.
   Air – clear water bead – is a colorless, odorless, tasteless gas. Air provides plants with life giving carbon dioxide. Plants “breathe in” the CO2 through their leaves and “breath out” oxygen. .
   Care – pink water bead – represents the care and nurturing on which plants thrive.
   Plant – green water bead – can represent a crop plant, tree, or anything they’d like to grow.
   
   After the Activity, Have students complete the following:
   1. Explore the What do Plants Need to Grow? worksheet either as a class or assign it to students to work through individually. Place the cards in the correct row based on the label at the top of each card. Then, arrange the cards in each row based on which plant needs it’s describing: water, air, nutrients or light.
   2. Review concepts with students.
   
   Activity 3: Needs of a Fish (Day 3)
   1. Ask the students, “What do you need to survive?” (food, water, air, and shelter) Ask the students if they think fish have the same or different needs. Discuss their responses and guide them to the understanding that fish have the same basic needs as humans.
   2. Provide each student with a copy of the Go Fishing! Worksheet in Google forms and the link to the interactive clickable fish to discover information about the needs of a fish in an aquaponics system. Students will click on the fish from our interactive webpage and use the information that each fish provides to fill in their worksheet through Google Forms.
   3. Review the basic needs of a fish by discussing the questions from the cards with the class.
   
   Set-up Aquaponics System Prior to Activity 4
   1. Watch this video for help setting up the aquaponics system: https://youtu.be/3c1cbBwiII8
   2. Find more helpful information for set-up on this website: https://backtotheroots.com/pages/water-garden-frequently-asked-questions
   
   
   Activity 4: Classroom Aquaponics (Day 4)
   1. Watch the video What is Aquaponics? to start exploring urban aquaponic systems.
   2. Review The Aquaponics Cycle using the linked diagram. Use the following points to facilitate discussion with students:
   
   Fish produce waste. The fish waste contains ammonia, which will poison the fish unless it is filtered out. In an aquaponics system, the water from the fish tank, including the fish waste, is pulled up to the plant trays through a pump.
   
   Microbes convert waste into nutrients. The ammonia in the fish waste that is present in the water being pumped into the plant trays is quickly converted into nitrite and nitrate by the bacteria naturally present in the trays.
   
   Plants filter the water that returns to the fish. Nitrates and nitrites are beneficial nutrients that are absorbed by the plants. This process filters the water. The clean water is drained back into the tank, providing a fresh source of water for the fish.
   
   3. Provide students with the Meeting Needs Activity Sheet. Ask the students, “What are the basic needs of plants?” (Plants need nutrients, water, air, and light.) Instruct the students to fill in the “Plants Needs” columns of the activity sheet with one of the basic needs of a plant in each row.
   4. Ask students if plants need water to come from rain, light to come from the sun, and nutrients to come from the soil. Discuss the concept that water, light, and nutrients can come from other sources.
   5. Discuss and record in the “Meeting Plant Needs” column how plant needs are met in an aquaponics system. Nutrients come from the fish waste, water comes from the fish tank, air comes from the classroom, and light comes from the grow light.
   6. Ask the students, “What are the basic needs of a fish?” (Fish need food, water, air, and shelter.) Instruct the students to fill in the “Fish Needs” column with one of the basic needs of a fish in each row.
   7. Discuss and record in the “Meeting Fish Needs” column how fish needs are met in an aquaponics system. Clean water comes from water that is filtered by the plants and drained into the fish tank, air is present in the water, and shelter is provided by the rock cave in the fish tank. Point out that food for the fish is not provided within the aquaponics system and must be provided for the fish each day. All of the fish and plant needs are taken care of within the system with the exception of food for the fish.
   8. Explain to students that your class will have a virtual aquaponics system that you will grow radish and wheat grass in. Show students the aquaponics and briefly describe the components of the system.
   9. Allow time each school day for students to see the aquaponics system and gather, record, and interpret data about the system’s water quality, water temperature, fish behavior, and plant growth. Using the data gathered, make adjustments as necessary to maintain a balanced system.

Extension Idea:
Use the recorded data to create a graph of the system’s temperature and pH over a two week period as the system is finding a symbiotic balance between plant and fish needs.