Wednesday, June 22, 2016

Aquaponics PBL - a Big Lesson in Focus & Scaling Back

For makerspace inspired Project Based Learning work this year in the library, fourth graders were given a choice of projects to work with.  One of the choices was to learn about aquaponics.  I first became interested in using the library as a place to spark interest in growing things after I read the School Library Journal article "Dig it! Library Gardens Sprout Up Coast to Coast" from August 2014.  I was completely amazed by the system set up by the Cranbury School in New Jersey and felt inspired to bring a more hands on sort of learning experience to my own students.

When I discovered a Back to The Roots aquaponics kit while doing a little Internet shopping, I realized that it
Kids unpacking the kit
could be a manageable task for elementary students. 

The Task:

Students were challenged to learn about aquaponics, figure out how to put an aquaponics system together and create a project that would teach others about aquaponics.

Key 4th Grade Standards Addressed:
  • NGSS - 3-5-ETS1-1 Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time or cost.
  • NGSS - 3-5 ETS 1-2 Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
  • NGSS - 3-5- ETS1-3 Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
  • CCSS - RI 4.1 - Explain procedures in a scientific or technical text, including what happened and why, based on specific evidence
  • CCSS RI 4.9 - Integrate information from two texts on the same topic in order to write or speak about the subject knowledgeably
  • CCSS W.4.7 Conduct short research projects that build knowledge through investigation of different aspects of a topic.
Across three classes, there were four groups of students who decided to research aquaponics. After some preliminary exploration of sources and conferencing, and a surprise donation of a 55 gallon fish tank to the library, the groups settled on one of two questions to guide research:
  • What is aquaponics, and what do we need to do to put the kit together and create a working system?
  • What is aquaponics and how can we create our own, unique system using a 55 gallon fish tank?  
For the groups researching the second question, they had to provide me with a list of the materials we were going to need to make a larger system so that I could write a PTO grant for the materials that we would need. 

Each group spent time creating a list of things that they would "need to know".  Their lists included things like: the type of fish we would need, where to put the tanks, how to create a healthy habitat for the fish and plants, and cost of materials.  They knew they couldn't go above $150 for the PTO grant. 


Throughout the research process, students use a standard set of graphic organizers that go along with the Big6 process.  They relied heavily on books that I had ordered about aquaponics, videos and articles from databases.

They asked me to set up a Padlet, where they could share ideas and resources they found that might help:

As research progress, through weekly conferencing it became obvious that all of the groups were really getting hung on the type of fish we could use in the system and creating a healthy habitat, while missing some of the critical ideas about where we were going to put the systems.

Each week I heard the kids discussing things like the ability to raise tilapia or trout, and the need to create a comforting environment for the well being of the fish.  While they were on topic, they weren't exactly on focus.  I found myself gently questioning them about daily research goals and if they were making progress towards those goals. They would shrug and say maybe not - and try to refocus. 

The original plans that the kids designed for the 55 gallon tank included two tanks that would utilize a flood and drain system, similiar to what our smaller kit was going to do.  After having a long hard discussion with the kids about space concerns for a system like this and with no obvious locations, we reached out to a University of Kentucky expert who was working with us on the Butterfly Garden project.  He suggested using a float and grow approach.  After some searching around, the kids were convinced it could work, and they gave me an idea of what we would need.  I took their suggestions and headed out to Worms Way ,a local aquaponics store, and the good folks out there helped me fill in the blanks on what we would need.

With the materials ordered, we decided that the best place to put the 55 gallon tank would be on the circulation desk.  The circulation desk is huge, has electric and could hold the weight of the tank and water. I put the tank into place for the kids and we were set to tackle the issue of filling it when we noticed something pretty important.  It doesn't sit flat on the desk! There are decorative ridges in the desk that create an uneven surface. 

The kids were under the impression that we should just try to fill it and see what happens, so I asked the kids what they thought would happen if we filled the tank like it was. "What will the tank weigh with water in it?" I asked them.  They looked up the average weight of a gallon of water and realized that the tank would weigh just under 500 pounds.  It became obvious to them that the weight alone would likely crack the tank and send water all over the library.

As groups, they began to look for alternative locations again, but by this time it was so late in the year I knew it was time to talk to them about scaling back the project.  As I was talking to them about how I thought we might have to save the 55 gallon tank for next year when they were in 5th grade, once we had time to sort out a solution to leveling my desk, I looked up on top of the bookshelf and saw an old fishbowl that has been there for quite a while and had an idea. "What if," I asked them "we used that fishbowl to prototype what you might do with the a larger tank.  Let's see if a float and grow system works using something much smaller."  The kids, although disappointed, rallied quickly and figured out that with a styrofoam ring and a small plant basket they could mimic the float and grow tray we had purchased.  

On the same day, the kids assembled the two different systems that we had, and the next day I went and bought two Betta fish for them to release into their systems.  On student direction, I also purchased some fake plants since they were very concerned about the Bettas having a place to hide so they would feel comfortable in their new habitat.


Both of the systems worked beautifully.  In the kit we purchased we grew wheat grass and radish sprouts and in the float and grow prototype system, the kids started a sunflower that we could transplant outdoors.  In the picture on the right, you can see the red Betta fish under the styrofoam float and grow prototype.

Future Plans

After the teachers began to take notice of some the things that have been happening in the library with PBL, I was able to talk tot he 5th grade science teacher about the possibility of using the 55 gallon tank for an aquaponics/ Trout in the Classroom type project.  With what we have all managed to learn, about setting up a system, and after talking to the kids to gauge their interest, it certainly seems like a possibility.  I plan to touch based with the 5th grade teacher at the beginning of school year and then work to follow up on some expert leads I've been given.


After seeing the difficulties we had with this project, I think one of the big takeaways I had was that we may have been much more successful had I sought out expert advice much sooner and maybe even partnered with a community organization to make it work.  Overall, I feel like we did hit the engineering standards in a natural way, and the kids for sure got some great lessons in research that I wanted.  When I debriefed with the kids on what their biggest takeaways were, they shared that they because they got too swept away with tank design and over the top fish research, they missed some opportunities to troubleshoot problems sooner. They seriously wondered if they would have stuck to the research questions each week, if the 55 gallon tank would have come together.  In our discussion I was able to reassure them that sometimes we find a thread that sparks our curiosity and we can't help pursuing it, and that's ok, but sometimes there are consequences to that.  It was a very real lesson on how to keep track of self-directed research, and I hope it's one they remember. 

The project was a great lesson in design and improving design to meet time and money constraints, and I really believe that the kids got some excellent practice in developing inquiry skills. One student remarked that it was the first time he had ever successfully helped to keep a fish alive, so by that standard alone it was a victory:)

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