Jason Axt from Sweet Water Foundation took my DIY class the other day … this was his feedback.
In my defense – I had 2 nine year old’s in my classroom as I did among others Kamal Hyder the author of ‘ ’embedded system design using the rabbit 3000 microprocessor’ – tough range to keep engaged.
Kijani Grows: Eric Maundu
American Steel Studios
3.8.2014 10am – 4pm
The class itself started with an overview of how the natural ecosystem deals with the water cycle and touched briefly on the nitrogen and carbon cycle without real specifics or depth into the complex biological reactions that make each cycle possible, but did use scientific terms. This understanding prepped the class for the day ahead and got all the students in the mindset to think of nature and how we act with nature.
Eric Maundu did an excellent job of drawing similar objects with first example of a circle and sun, driving home the idea that he is not here to teach aquaponics, but core understandings of shapes, relationships, natural cycles/ biology, and basic science. He used aquaponics and his aquaponic design as a tool to showcase his understanding of mimicking biology, and just as in nature when humans begin to intervene, things begin to become imbalanced. He smoothly transitioned this understanding to his justification of his designed gardens, showing us that his combined garden design and linux based controllers are a better means to keep things running as nature intended than any human operated system.
After about an hour and a half of overview of the water, carbon, and nitrogen cycle and how they transfer to aquaponic gardens, we then began to build our gardens. Without a brief tutorial of the design and tools used to fabricate the wood pieces, Eric dove into the fabrication process with sanding, epoxy resin construction on the wood panels of the garden grow bed. Each student fabricated his or her own garden, allowing for the student to take home a garden they built at the end of the day, which is understood to be the core drive of the class.
Once the first coat of epoxy was applied, we ate lunch and allowed Eric to continue with the more technical aspects of the aquaponic system. Eric explained about the nitrogen cycle in terms of cycling with initial spikes in ammonia, then nitrite, and finally nitrate. He did a good job of teaching the basics of the nitrogen cycle, but in respect to the carbon and phosphorous cycle, a lot of questions were still left unanswered. The water cycle was clearly mimicked with the use of a pump, but Eric did not explain well how his garden is to be optimally operated with the use of timers, fish, feed, and lights for plants. He did make it clear that it was not a specific ratio needed for aquaponics to work, but instead chose what you like to grow and work with the ratios to optimize your garden. Then we moved back to the fabrication of our gardens.
If our garden’s first epoxy layer had dried, we applied assembled our garden, applied another epoxy layer sealing cracks and gaps, and finally sealed all corners and edges with epoxy based silicone. Each process was lengthy and it seemed that the class was beginning to run out of time based on the process of epoxy curing and the increased urgency to finish. When the class finished, the students were left with an unfinished product and an unclear understanding of how to operate this garden. The class of four to five then fizzled out as a new group of students came in to ask Eric about his work.
The beginning “why aquaponics” section of class was a great aspect for understanding how aquaponics mimics nature and the similarities in pattern language between nature and aquaponics are. The picture of the large ecosystem to the drawing of the aquaponic systems was one of the best representations of biomimicry principles I have seen in recent educational material on aquaponics. This introduction really energized the students to dive into producing their own example of nature for their home.
As we transitioned to building our system, it seemed like some prep work needed to be done so the building could be taught and then mimicked by the students fluently without major distraction. Instead time was spent prepping the work table for the beginnings of the project. It should be easy to cut down on wasted time by making sure that the pieces and table are prepped for each student whom arrives and the work bench is ready for epoxy work. The epoxy resin construction seemed to take a very long time to apply and cure. This allowed for the students whom were not as focused on their garden to begin to wonder. This process might be curbed by switching material of wood and epoxy to something more immediately waterproof or having the initial epoxy surfaces prepped for the class making the first stage of construction assembling the pieces together to form the grow beds and sealing the garden. This would allow more time for the final epoxy to cure during lunch and the second half of the class, allowing the garden to leave not sticky. Also this single application of epoxy allows for a tutorial of the operations of the system at the end of class. Any further questions can be vetted out with an understanding of the operations, and possibly a manual to take home. The manual should include suggestions on rocks, fish, lights, and plants to get started with.
In regards with the second half of the class’s technical learning, this seemed to be the least important aspect of the class. The importance of understanding how the garden operates chemically is almost an afterthought due to the gardens quick ability to cycle and operate optimally, leaving the need for deep understanding of the process and possible troubleshooting behind. I would have liked to see the chemical equations on oxidation of the nitrogen cycle, and more detail on how the carbon and phosphorous cycle play into this aquaponic system. I did like the filter design for aquaculture section, but for this garden it may not be as necessary. The most important aspect of this section of class is obviously teaching how bacteria grow. Once the core concepts of how bacteria grow are understood then the relationship to filter design and filtration methods should make more sense. I did like the clear indication that the problem is not growing fish or growing plants, but instead the problem to solve is growing bacteria. That was very clear and a great thing to teach when many aquaponic classes focus more upon fish and plants which I believe are less important to understand in building a system.
After the class, the moms brought up some good unanswered questions on how much light do the plants need and what kind of light should be bought to best grow plants? Also what kind of fish can I put in this system, and what else do I need for this system? I think an exit manual or take home sheet describing a successful system and some operational hints or techniques would really give confidence to the new owner of the systems. Also this could be used in your packaged systems for product sales.
Overall, it is a really fantastic class, a great marriage between static and active learning. The timing and sequencing of the class is spot on. There are only a few things I would do to minimize the questions at the end of class, and provide more confidence to the student.
- Jason Axt