FOOD FROM FISH POOP?!

Transcription

1 LESSON SUMMARY: Students will learn about aquaponic systems and how to grow nutritious food from live fish by-products AN AQUAPONICS FACILITY GROWING TOMATOES

2 ACKNOWLEDGMENT This guide was created with the invaluable assistance of WaterFarmers of Toronto, Ontario. Aquaponics is a growing field of study and application and there are great opportunities for innovation. Perhaps some of your students will be the ones to take aquaponics to another level. For more information about aquaponics please visit 2

3 ACTIVITY INFORMATION CURRICULUM CONNECTIONS GRADE LEVEL: Senior GEOGRAPHY: Human-environment interactions ESTIMATED DURATION: A semester or year MATERIALS: See materials list SCIENCE: Health, biology, botany, engineering, physics, hydrodynamics SETTING: KEY VOCABULARY: Indoors/outdoors Sustainability, biodiversity, eco-system ENVIRONMENTAL SCIENCE: Sustainability TOPIC: There are alternative methods to growing healthy food. Many of which could be used to address food insecurity. LEARNING GOALS 1. To understand plant life cycles 2. To recognize alternative methods for vegetable growth and build a working aquaponics system 3. To understand why aquaponics works and to examine its applications 4. To grow a healthy crop of vegetables 3

4 ACTIVITY Using the following detailed instructions assemble your own aquaponics systems in your classroom. Over the course of a semester your students will learn about keeping fish healthy, the life cycle of a plant and the pride of growing life-sustaining vegetables from seed using nothing but fish waste, water and sunlight. EXTENSION Your aquaponics installation could be built in your school s lobby for other students and visitors to enjoy and learn about. Additionally, group research projects could be assigned to further examine the individual components and processes involved in aquaponics. 4

5 TEACHING AQUAPONICS IN THE CLASSROOM From pre-school to postsecondary, aquaponic systems provide interactive educational and research opportunities while also producing healthy local food. Small-scale systems in the classroom introduce students to a variety of STEM concepts and related food security issues, while university partnerships create capacity for exciting research projects across a number of fields. WHAT IS AN AQUAPONIC SYSTEM? Aquaponics is the integration of hydroponic plant production within a recirculating aquaculture system. Hydroponic production grows plants in water using a nutrient solution appropriate for the chosen crop, while a recirculating aquaculture system grows fish using water maintained by a filter system. In an aquaponic system, this nutrient-rich fish waste is consumed by helpful bacteria and microbes, which generate an excellent natural fertilizer for the plants in the same system. Waste (poo, manure, effluent, etc) created in the fish tank flows through a series of filters, and then into the plant production unit before returning to the fish tank. Toxic ammonia in fish waste water is converted to safer nitrogen compounds by microbes living in the system. Microbes play a key role in this natural nitrification process by creating plant food from waste, similar to a compost pile. Plants are then able to use this nitrogen as building blocks to conduct photosynthesis and grow. As an added benefit, this water can then be returned to the fish tank as cleaned water with less ammonia. Plants, fish, and microbes thrive in a balanced symbiotic relationship. 5

6 DIY SIMPLE AQUAPONICS SYSTEM Adapted from WikiHow System Developed by Japan Aquaponics This module explains how you can build a small-scale aquaponic system using commonly available components from online sources and your local hardware store. This is an extremely basic set-up so please do make sure that you follow up with learning how to manage your new system to look after the fish, the plants and microbes! WaterFarmers staff will have a similar complete kit system on hand during the Royal Agricultural Winter Fair for pre-order and setup. MATERIALS 2-tier cart/frame (IKEA Antonius frame) 50 litre or similar plastic tote fish tank 25 litre or similar plastic tote for grow bed small 50 gph ( lph) submersible pump with foam prefilter growing media: washed river stone (1/2 or similar), or hydroton (expanded clay aggregate) ball valve plumbing pipe and fittings bulkhead fitting fish & fish care products water quality test kit seeds 6

7 INSTRUCTIONS Step 1 - Frame Set Up Use the Antonius frame and two plastic containers to make your grow bed and fish tank. Use the small container on top inside the wire basket, and the large container resting on the ground below or whatever your situation requires. 7

8 INSTRUCTIONS Step 2 - Plumbing The plumbing for the aquaponics system is relatively straightforward, and can be completed with hard pvc plumbing pipe, or flexible hose as a hands-on DIY lab or classroom activity. Use a small 50 GPM (gallons per hour) pump in one corner of the fish tank. Water flows up from the fish tank, into the grow bed, and exists the opposite corner back into the fish tank. 8

9 INSTRUCTIONS Step 3 - Media Bed and Gravel Guard Using a hole saw appropriate for your bulkhead fitting, drill a hole in the grow bed container. Make sure the bulkhead will fit through the wire basket. A gravel guard can be made with a short length of 3 or 4 sewer pipe, with drainage holes cut or sawn into the sides. This will ensure water can drain back into the fish tank, while keeping the gravel and roots in the media bed. Use a cap to keep gravel from falling into the fish tank. 9

10 INSTRUCTIONS Step 4 - Bypass Ball Valve Add the pump bypass using a tee and ball valve. This allows you to divert water back to the fish tank, providing additional aeration and metering the flow to the gravel media bed. 10

11 INSTRUCTIONS Step 5 - Completion and Maintenance Fill the media bed with gravel, hydroton or whatever non-toxic growing media you have chosen. Fill the fish tank with water, plug the pump in and test for leaks. Use the by-pass valve to reduce the flow to the grow bed, circulating a portion of water through the fish tank. Once this is done, you are ready to add your fish and plants to the system! Start with low numbers (5-7) of goldfish, tilapia or other fish to start the aquaponic process. Feed sparingly initially until the water chemistry stabilizes. Use a freshwater test kit (great for easy chemistry labs) to test ph and ammonia levels. Try easy varieties like lettuce, basil or kale. Ensure your system has lots of light near a window, or add a grow light. 11

12 CONGRATULATIONS! You have started up your first aquaponic system. Read up online for more resources to gain a thorough understanding of the processes involved depending on teaching priorities. Contact WaterFarmers for more detailed instructions or to purchase aquaponic materials. 12