- Vegetables: greens (leafy), greens (lettuces)
- Additional Plants: herbs
- Crop Production: fertilizers, seed saving
- Production Systems: aquaponics, hydroponics
[Editor's Note: To view this report with graphic and photos, open the attached version.]
Sustainable Agriculture: Instruction, Application, and Community Outreach Utilizing Recirculating Aquaponics Systems
Youth Educator Sustainable Agriculture Grant
March, 2013 – March, 2015
Kevin M. Savage and Gary A. Delanoy
Cincinnati Hills Christian Academy
11525 Snider Road
Cincinnati, OH 45249
March 26, 2015
We would like to acknowledge the North-Central Region of Sustainable Agriculture Research and Education (NCR-SARE) for providing the initial significant funding to grow the Sustainable and Urban Agriculture / Aquaponics program at Cincinnati Hills Christian Academy (CHCA). Although the initial grant award of $2000 may seem to be a relative small amount to many, the money awarded has served as both internal and external seed money, and we believe that the investment of this award by NCR-SARE has paid dividends for the students and faculty at CHCA, as well as those impacted by community outreach.
We also acknowledge the financial and administrative support of CHCA, especially Dr. Dean Nicholas (High School Principal), Dr. Lu Taylor (High School Science Department Head) and Heather Wilkowski (Director of High School Operations). Mark Bishop and Tyler Eifert of CHCA’s Facilities Management team provided invaluable assistance with construction projects in our laboratory. The students of Environmental Science I and II of academic years 2013-2014, and 2014-2015 are responsible for the construction and operation of various aquaponics systems presented in this report.
Finally, we would like to acknowledge CHCA alumnus Nick Elder (Class of 2014) for his design of the CHCA Aquaponics logo. Nick was a student in the Sustainable and Urban Agriculture course in 2013-14. He designed the logo (shown on the title sheet of this report, and below in larger format) to (1) include both of the “fish and produce” components of a recirculating aquaponics system, and (2) the globe in the background to acknowledge the potential global impact of sustainable agriculture in general, and aquaponics, specifically, in helping to meet food needs. Nick also incorporated CHCA’s school colors (deep purple (fish), and forest green (plants)) into the logo to subtly include CHCA as a part of the sustainable agriculture education process.
This project focused on recirculating aquaponics systems as a closed-loop form of sustainable agriculture. Aquaponic gardening as a sustainable agriculture method is not a new method, having been refined and implemented on a large scale at the University of the Virgin Islands some 30 years ago. It is, however, a relatively new teaching tool in secondary science classrooms. Over the past four years, faculty at Cincinnati Hills Christian Academy (CHCA) have utilized aquaponic systems to teach and reinforce science concepts that are intimately related to sustainable agriculture, all within a traditional high school course sequence: botany, seed germination, plant growth, pollination, biogeochemistry and plant nutrients (Biology), biogeochemistry of natural systems, and chemistry of aquatic systems (Chemistry), biogeochemical cycling, urban agriculture, and sustainable agriculture (Environmental Science). Over the course of a four-year curriculum, students learn the basics of aquaponics as a method of sustainable agriculture, and then have the opportunity to apply their knowledge through the design, construction, operation, and monitoring of a fully-functioning aquaponics system. The upper level students also explore the “end products” of sustainable agriculture through exposure to “food deserts”, and the connection between access to fresh produce and protein and effects of lack of good nutrition on the overall health and fitness of those who lack access. Additionally, implementation of a variety of aquaponic system types has created opportunities for students and faculty to engage in independent research, as well as collaborative research with a local university. Finally, interaction with the community outside of CHCA has allowed students and faculty alike to experience a transfer of knowledge and skills gained in a classroom setting to the “real world”.
The funds awarded to CHCA through Youth Educator Grant YENC13-067 have been used to construct and facilitate initial operation of a large vertical tower aquaponics system. As constructed, the system consists of twelve (12) ZipGrow® towers (each tower is five feet in length) from Bright Agrotech, LLC (www.brightagrotech.com), a 100-gallon stock tank for the fish, an external biofilter, and all of the associated plumbing to connect the various components, and woodwork for framing and to provide structural support.
The system design was completed with technical assistance and guidance from Dr. Nate Storey of Bright Agrotech, LLC; system construction, including plumbing, was completed by students in the Environmental Science I & II (Sustainable & Urban Agriculture) course sequence working under faculty supervision. The system, as shown below in Figure 1, consists of ZipGrow® towers mounted in a wooden framework at 8-inch, on-center spacing to replicate standard spacing between rows in other aquaponic systems, as well as traditional soil garden systems. The tops of the towers are approximately 7’ 4” above the laboratory floor; this allowed placement of a single gutter-type drain system to catch water flowing downward through the towers, and return the water to the fish tank. This height also allows the fish tank to fit vertically beneath the gutter to allow all “return” water movement to be gravity-driven, eliminating the need for an intermediate sump and water pump. Fish tank water, containing dissolved fish waste, fish waste solids, and uneaten fish food, is drained from the bottom of the fish tank to the biofilter by hydrostatic pressure from the water in the fish tank (Figure 2). Water flows into the top of the biofilter, where woven filter media removes the majority of suspended solids, and allows low turbidity water to flow downward into the biologically-active portion of the filter where nitrifying bacteria convert the dissolved fish waste (principally ammonia, NH3) into nitrite (NO2-), and the nitrite into nitrate (NO3-).
The water reaching the bottom of the biofilter, now enriched with nitrate, is pumped via irrigation tubing to the top of each tower, where it trickles downward over and through the root system of the plants in the tower. The nitrate is taken up by the plants as a source of nutrition, and water with lower nitrate concentrations is returned to the fish tank to complete the flow cycle. As constructed, the entire system (including fish tank and external biofilter) occupies only 20 square feet of laboratory floor space, but provides more than 60 square feet of growing space.
Because the system has been constructed in an interior laboratory of the school, it was necessary to add grow lighting for the system. The grow lighting consists of two Sunblaze Sunsystem 48 T-5 High Intensity Discharge light units mounted vertically to maximize light coverage for the towers. One light is mounted in a rolling frame which allows the light unit to be moved to allow access to the towers for planting, measuring, harvesting, and periodic maintenance and cleaning. Because of the fish tank, the second lighting unit could not be placed on a rolling frame. Instead, the students brainstormed, and designed a frame for the fixture, which is mounted to a flat-screen television wall mounting unit; this allows the fixture to be moved into, and out of position in front of the towers for access (Figure 3).
Students select crops, and then seeds from the CHCA Organic & Heirloom Seed library for planting. Over the course of this project a variety of media were utilized for seed planting and germinating, but the two primary media were Grodan A-OK 1.5” rockwool starter plugs, and GrowTech Flexicube 1” starter plugs. Plants selected for growing in the vertical tower system have included Genovese basil (Figure 4), Thai basil, mesculun lettuce blend, Russian kale, cilantro, marjoram, sage, Swiss chard. All have grown successfully, and thrive in the tower system. As plants reach maturity, they are harvested by the students (Figures 5 & 6).
Students record relevant data on logging sheets with each system, including date of seed planting, date of harvest into the tower system, date of harvest, age of the plant at harvest (from seeding), and biomass of the harvest. At present, students are developing planting schedules, based on observed germination and growth-to-maturity times to allow cyclical planting, growing, and harvesting of the towers.
Students in the Sustainable and Urban Agriculture course are responsible for ongoing operation and maintenance of the vertical tower system, as well as six additional aquaponic systems of various configurations in the CHCA Aquaponics Laboratory. Students test water chemistry (Figure 7), monitor fish tanks for water level and cleaning needs (including identification and removal of dead fish), keep automatic fish feeders filled, provide periodic cleaning of solids filter media in the biofilters, monitor plant growth, and check regularly for insects and other pests in and around the grow beds. As a part of water quality testing, students and faculty together identified the key parameters to provide assessment of the health of the water, and which parameters need to be monitored on a (a) daily, (b) weekly, and (c) monthly basis. A water quality monitoring data sheet was developed, and is used by students to ensure completeness in the data collection.
In addition to all of the tasks associated with the plant portion of the system, students also are responsible for care, and data collection activities associated with the fish portion of the system. The fish in the system are a mix of Nile and blue tilapia (Oreochromis niloticus, and Oreochromis aureus, respectively) obtained as fingerlings (1 – 5 grams in size) from the Shekinah Ranch Aquaculture Center in Dayton, OH. Fish growth is monitored by periodic measurement of a random selection of fish. As the fish grow to harvest size (500-600 grams), students will be taught proper technique for sacrificing the fish, as well as proper techniques for filleting the fish for use as a food item (Figures 8 & 9). Fish harvesting and euthanasia is completed under faculty supervision, and the guidance/direction of a Livestock Care Plan found to be “acceptable”, and in compliance with euthanasia guidelines by the American Veterinary Medical Association. Copies of the Livestock Care Plan are labeled and posted in the aquaponics laboratory.
The tower system in its present configuration has been fully operational for six months, at the time of this writing. It has become the “showpiece” system in the laboratory, and is a popular tour stop for visitors to CHCA. Maturing Nile and blue tilapia populate the fish tank. Multiple, regular harvests of basil and lettuce, as well as intermittent harvests of sage, marjoram, cilantro, chard and kale have been made. Presently (March, 2015), all twelve towers are populated with a variety of plant types in different stages of growth. As plants mature later this spring, we will be allowing some of the plants to “bolt”, and produce flowers and seeds, which the students will collect, process, and store as a part of the sustainable agriculture curriculum. Plans for this spring also include growing strawberries in 1-2 towers, and a small project to test how well several varieties of hops will grow in the system.
Curriculum Development / Specific Practices Learned
Aquaponics initially became a part of the CHCA culture in 2011, when students in the Environmental Science class taught by Dr. Savage constructed a five column, vertical recirculating system using a 65-gallon aquarium, and recycled two-liter soda bottles with expanded shale media as the growing columns. This initial system was constructed as a component of a semester-long unit on agriculture and food systems, and represented an early attempt to build and operate a small-scale, sustainable crop-producing system. Though crude and somewhat rough in appearance, this system has operated continuously since its completion; the system has produced harvests which included bell peppers, hot peppers, leaf greens, kale, sweet and purple basil, and lemon balm.
Since that initial system, we and our students have constructed and operated a number of other small-systems, including rafts of basil, and leaf greens floating directly in an aquarium, and hybrid systems with media-filled and deep-water culture (DWC), or raft, beds. Systems constructed by students during the 2013-14, and 2014-15 school years include the vertical tower system funded by this NCR-SARE Youth Educator Grant, two “Barrelponics” systems (funded by a grant from the Aquaponics Association and matching funds from CHCA), and three media-filled grow bed systems. The fish component of these systems has included channel catfish, hybrid bluegill, and yellow perch, in addition to the tilapia presently being used. Although produce production in these systems has varied widely, the fish have thrived and grown to harvest size, and each system has afforded us and the students the opportunity to gain invaluable experience in the day-to-day operation of different types of aquaponics systems.
Aquaponics in the Curriculum: Since construction of the initial system, we have worked to create units or modules that utilize aquaponics to teach both basic and advanced topics in courses offered as a part of a four-year science curriculum at CHCA. Development of additional modules continues to be a work in progress; specific topics for development are impacted by year-to-year changes in course teaching responsibilities. Basic modules by grade level / course are described below.
Students at CHCA are introduced to aquaponics in freshman (9th grade) biology classes, where aquaponics is used as the basis for such learning modules as aquatic ecosystems, basic microbiology, and chemistry of natural waters. In sophomore (10th grade) chemistry, aquaponics is again utilized as the basis for modules including pH, oxidation-reduction reactions, and multi-parameter water quality testing using a variety of test-strip, wet chemistry, and probe methods for monitoring. Modules for design and construction of air lift pump systems for moving water within an aquaponics system have been outlined for use in the 11th and 12th grade physics course sequence as a part of a fluid dynamics unit; to date, however, the physics instructors have shown little interest in aquaponics, or the inclusion of this module into the physics curriculum. Beginning in 2015-16, this air lift pump module will be incorporated into the Sustainable and Urban Agriculture course curriculum.
Juniors and seniors are eligible to take the Environmental Science I & II elective course sequence. This sequence is our Sustainable and Urban Agriculture course; it provides an introduction to traditional agriculture and modern industrial agriculture, but focuses on sustainable and urban agriculture using aquaponics as the primary teaching tool. This class builds upon the experiences students have had with aquaponics in other courses, but spends significant time in the principles of aquaponics (including modules on plant and fish biology, and microbiology), the basics of design for a variety of system types, hands-on construction of one or more type of system, and operation and maintenance of multiple systems which are in the laboratory. A detailed syllabus for this course is in Appendix A of this report. In general, the first academic quarter is spent learning the role of sustainable agriculture in a global context, and the “detailed basics” of aquaponics. An emphasis is placed on an understanding of aquaponics as a “designed and constructed polyculture ecosystem”, rather than simply as the melding of the sustainable agriculture methods of aquaculture (fish farming) and hydroponics (plants grown without being rooted in soil). This approach keeps the emphasis on the need to maintain system conditions that benefit all of the living components, as well as the interdependent and symbiotic relationships between the living components. In the second quarter, students use their previously-acquired math and science skills, together with their newly-gained knowledge of aquaponics system components and system types to design, and then construct a new aquaponics system. During this phase, students gain practical, hands-on experience in learning to safely operate power tools for simple carpentry tasks, and skills in fabricating plumbing systems with PVC and flexible irrigation-type tubing and fittings. Leak-testing provides an opportunity for troubleshooting and problem solving. The addition of fish, plants, and nitrifying bacteria mark the operational launch of the new system, and a transition to the operation and maintenance mode, with all of the previously described tasks related to care of the fish, plants and bacteria.
Beginning in the second quarter, and continuing through the third quarter, students explore traditional and industrial farming, food processing and production, wholesale distribution, and retail distribution of food using a curriculum entitled “Teaching the Food System”, produced by the Center for a Livable Future at Johns Hopkins University. Aquaponic system operation and maintenance tasks continue as on-going activities throughout the third quarter. In the fourth quarter, students focus on land use and land management, with an emphasis on agricultural land use applications.
Specific Practices Learned: In the initial grant proposal, we identified 11 specific practices that our student would be exposed to, with an expectation of at least a rudimentary demonstration of mastery. These practices are identified in Table 1 below; the second column of the table identifies where in the Sustainable & Urban Agriculture course structure a specific practice is introduced and/or explore in depth.
Aquaponics and Research: In addition to the core and elective course offerings involving aquaponics, a Research and Leadership program at CHCA provides students with the opportunity to pursue independent research during their 11th and 12th grade years. At the time of this writing, there are five students conducting research in aquaponics under our direction, and with additional guidance from aquaponics professionals outside of the school community, and research faculty & doctoral students from the University of Cincinnati. Two students are currently completing their two-year projects, and will be presenting the results of their work as a capstone presentation and document in late April or early May of 2015. The remaining students will be seniors (2) and one junior next academic year, and will be continuing the collaborative projects with the University of Cincinnati personnel. In addition to the internal capstone presentation and document, each student has a requirement to share the results of their work with the aquaponics community at large by presentation at professional meetings, publication, or both.
Future Direction: As the aquaponics program at CHCA continues to grow and evolve, we continue with the task of updating existing curriculum modules, and developing new modules to be consistent with guidelines and objectives identified in the Next Generation Science Standards (NGSS). The State of Ohio is a lead-state partner involved with the development and implementation of these standards, and revision and on-going development of new modules that are consistent with NGSS objectives is a priority for our program. Development work and refinement of existing modules to fit within the paradigm of STEAM (Science, Technology, Engineering, Agriculture, and Mathematics) is also underway. Preliminary results of these efforts were presented in February, 2015 at the Environmental Education Council of Ohio’s “Winter Snow STEM Conference” in Perrysville, Ohio.
Planning is presently underway for the 2015-2016 academic year to include financial modules into the Sustainable and Urban Agriculture course, so that students will be exposed to the “money” side of aquaponics, including fixed costs of system design and construction, on-going operation and maintenance costs. Future planning beyond the 2015-2016 academic year will include an extended module on business plan preparation as a part of CHCA’s Social Entrepreneurship program.
Aquaponics in the Community
As a Christ-centered institution, faculty and students at CHCA are actively engaged in service opportunities at the local, regional, national, and international levels. An individual’s involvement in a given opportunity is typically a reflection of her or his personal passion.
Over the past year, we have been fortunate to have been involved in two significant projects involving aquaponics in the greater Cincinnati community. During July and August of 2013, the Cincinnati Park Board’s Krohn Conservatory hosted an exhibit focused on sustainable agriculture methods called “Let It Grow.” The exhibit included aeroponics, hydroponics, and vertical gardening, but the centerpiece of the exhibit was a large aquaponics system with both deep water culture and dutch bucket components. We provided water-quality monitoring at a system prototype during the spring and early summer, and were invited to assist with installation of the exhibit (Figures 10 & 11), and subsequently provided regular water-quality monitoring through the duration of the exhibit, as well as a Saturday community lecture for Conservatory patrons.
Also in July 2013, the Cincinnati Zoo and Botanical Gardens completed construction of a greenhouse to house two hybrid media bed and deep water culture bed aquaponics systems (Figure 12). We worked with the same core group of aquaponics professionals, and again provided water-quality testing support for this project during system start-up. CHCA faculty and students have continued to coordinate with Zoo staff to provide water quality testing on an on-going basis. Produce being grown in these systems is being used by the executive chef of the Zoo’s sustainable restaurant, called The Base Camp Café.
Additionally, we are in the initial stages of proposing and (hopefully) developing a plan for CHCA students and faculty to assist with an aquaponics system at a local community service agency called Gabriel’s Place, in the Cincinnati community of Avondale. It is hoped that this can be in place for the 2015-16 school year.
A presentation was given at the 2014 Farmers Forum, held in conjuction with the Ohio Ecological Food and Farm Association (OEFFA) Conference. A recording of this is available online through NCR-SARE's YouTube channel at the following link: https://youtu.be/d2rZQQ2Ofpc
This project, and the funding provided by NCR-SARE, has been the single largest impetus behind the growth and development of the aquaponics program at CHCA. Through this project, students and faculty have gained invaluable insight into the design, construction, and successful operation of aquaponic systems. This has opened the door for students and faculty alike to share the results of classroom instruction and research as formal presentations at a variety of professional conferences and meetings (see Appendix C for title slides of presentation). The opportunity to present has increased the level of credibility of the program, creating an opportunity for CHCA students and faculty to be active principal researchers in a long-term cooperative research program with Ph.D. students and research faculty from the Chemistry Department at the University of Cincinnati. Increased credibility has also opened the door for us to begin to be able to introduce aquaponics as a dynamic model for classroom STEM instruction to other secondary educators as instructors of a one-day workshop offered through the Greenacres Foundation (http://www.green-acres.org/) in Cincinnati, Ohio, and the University of Cincinnati.
Award of the Youth Educator Grant was instrumental in our program being awarded a $1000 microgrant from the Aquaponics Association (http://www.aquaponics-assoc.org/) and an additional $1000 matching grant from CHCA to fund design and construction of two “Barrelponics” hybrid aquaponic systems. One system is being donated to an urban elementary school for use as a part of a multi-grade science program. CHCA faculty and students will be involved in the transfer and installation of the system at the new school, and in providing mentoring and instruction to the teaching staff at the school to be able to successfully operate the system.
Through the curriculum and outreach components of the project, we have been able to refine and focus the vision for the short-term continued growth and development of the program. We have also been able to use all of the tasks completed as a part of this project to lay the groundwork for a significant growth step program: installation of a multi-bay, on-campus greenhouse to support (1) classroom instruction, (2) multi-disciplinary student and faculty research, and (3) operation of a small, commercial-type system as a micro-business enterprise under the CHCA Social Entrepreneurship Program.
As classroom instructors and research mentors, we are extremely grateful for the financial support and professional encouragement of NCR-SARE, and the NCR-SARE staff. We whole-heartedly endorse the Youth Educator Grant program as providing financial assistance to allow educators to attempt and implement non-traditional and innovative approaches to classroom instruction. We give the program our strongest endorsement, and would encourage our education colleagues to actively pursue funding opportunities through NCR-SARE.
Project Budget Status
Project expenditures to date total $1475.46, as shown in the Final Budget Summary table below. At present, our expenditures are $537.54 below our proposed project budget. It is our intent to use the balance of these funds to support “consumable” expenses associated with continued operation of the system until such time as the funding is exhausted. The consumable expenses are (1) water quality test kits to monitor the “health” of the system, (2) fish feed, and (3) additional fingerlings to replace fish which reach maturity and are harvested.