Pathways to Produce: Learning to Maximize Aquaponics Systems for Local Food Production

Final report for YENC20-148

Project Type: Youth Educator
Funds awarded in 2020: $4,000.00
Projected End Date: 12/31/2022
Grant Recipient: Saint Louis Science Center Foundation
Region: North Central
State: Missouri
Project Manager:
Beth Kastner
Saint Louis Science Center Foundation
Project Co-Managers:
Maddie Earnest
Saint Louis Science Center
Pattie LaBrott
Saint Louis Science Center
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Project Information


This project will harness the aquaponics greenhouse’s capacity as a learning laboratory for aquaponics management and will educate and inspire youth through both informal science education and internships. A micronutrient solution will be incorporated into an established aquaponics system as an experiment to improve plant performance and results will be shared with and directly observed by young visitors. Youth interns will take the lead on measuring crop performance and communicating lessons learned through online blog postings and visitor interactions. Improved signage will address hydro/aquaponics as sustainable sources for local urban production of certain crops and highlight related career opportunities.

Project Objectives:
  1. Engage and educate youth on the technical challenges of indoor and aquaponics food production while implementing a revised nutrient supplement process.
  2. Showcase the iterative process of troubleshooting a typical aquaponics system and teach visiting families and youth audiences about sustainable agriculture.
  3. Engage families in demonstrations and discussions about the profitability, sustainability, and community benefits of urban agriculture through the GROW gallery and SciFest community events.
  4. Engage urban students in aquaponics through sustainable-agriculture-themed field trips.
  5. Communicate information on aquaponics via blog postings, visitor engagement, and enhanced signage in the greenhouse.
  6. Provide aquaponics training and agriculture-career information to teen interns.

Educational & Outreach Activities

1 Tours
11 Other educational activities: Blogs were produced.

Participation Summary:

176 Youth
4 Educators
Education/outreach description:

NOTE: This list has been amended due to the temporary restrictions and closures of the Saint Louis Science Center that began in March 2020, due to the COVID-19 pandemic.

January – March 2020: Plant and Animal Manager Hannah Reinhart and Senior Educator Andy Senters began documenting the status of the aquaponics greenhouse crops and fish and continued incorporating a revised iron and potassium nutrient solution into the existing 3,000-gallon aquaponics system. Nutrient solution applications were continued every three weeks. The aquaponics greenhouse was open to visitors to explore and to engage in daily afternoon fish feedings before the museum’s temporary closure in March.

March 2020 – May 2020:  Hannah and Andy noticed nutrient burn on plants in April.   The solution appeared to be creating negative impacts on the plants. Additionally, the iron turned the water red, and it was now impossible for staff or guests to view the fish. This was an unintended consequence of the solution.  The staff discontinued the use of the solution and worked to regulate levels in the water.

June 2020 – December 2020:  Staff continued to operate the greenhouse.  Staff did not do tours but were available often to speak with guests regarding the greenhouse and greenhouse systems.

December 2020-March 2021

Because the nutrient solution was no longer viable, staff determined new ways of running some trials.  Hannah planted a mix of different lettuce varieties to determine which would do the best in the floating raft. See attached notations on this trial.

March – May 2021

GROW staff and STEM (science, technology, engineering, and math) content developer Angela Mele created content for improved signage on sustainable agriculture inside the greenhouse. This signage gives visitors greater detail on hydroponic and aquaponic systems displayed in the greenhouse. Each system is labeled and allows our guests to self-direct. There is additional signage highlighting local farmers and promoting careers in indoor farming.

May – July 2021:

GROW staff were able to host a summer intern candidate from the Science Center’s Youth Exploring Science (YES) program. The intern worked in the aquaponics greenhouse, helped inform visitors about sustainable urban agriculture, and started a blog about the crop-production progress in the greenhouse. June and July blog posts are listed below:

June 17, 2021:

June 19, 2021:

July 2, 2021:

July 8, 2021:

August – September 2021: GROW’s summer intern, Christopher, remained actively engaged in GROW and was supervised by the Senior Educator as they helped maintain, monitor, and measure aquaponics crop production. Observations on the greenhouse crops continued to be shared with the community through blog postings and daily visitor interactions. 

As the blog continued throughout the summer, it was highlighted on the SLSC website. It included discussions about sustainable agriculture and careers in agriculture. The August and September blog posts are listed below:

August 10, 2021:

August 14, 2021:

August 23, 2021:

August 31, 2021:

September 7, 2021:

October 2021 – January 2022: GROW staff  were unable to host two fall aquaponics field trips as planned due to COVID-19 restrictions. The Science Center made the difficult decision to temporarily close again due to COVID-19 on January 17, 2022. The current date set for re-opening to the public is February 3, 2022.

Hannah experimented with peat pellets as a medium for seed starting. She put together a blog post about this.

January – February 2022:  The deep-water floating raft area had to be decommissioned due to a leak that could not be repaired without replacing the pond liner. The pond liner is on backorder and all trials are shut down until the repair can be made. Assuming repairs are made by the end of February, Hannah will again trial the peat pellets as use for the growing media and compare them to the soil based starting method usually employed.  

February – April 2022: Youth engagement around the greenhouse will continue to include greenhouse tours, public fish feedings, blog and website articles, and Facebook and Twitter announcements about GROW.

GROW will participate in the Science Center’s Engineering Expo SciFest - which explores engineering and technology and will include displays and discussions about established practices and new innovations in agriculture – if the event proceeds as scheduled. GROW has invited Vast Produce and SquareFruit labs to speak about their work in hydroponics and aquaponics at SciFest.

May – September 2022: Two Junior Interns were trained in aquaponics and sustainable agriculture, spending significant time in the greenhouse while maintaining the system and adding content to the blog and social media feeds. The YES Teen who participated in GROW in 2021 completed his first year of college.  They enjoyed the program so much that he returned in the summer of 2022 and worked as a Science Center employee.  Following is our final Science Center Blog for 2022:

October – December 2022: GROW and aquaponics hosted field trips reaching 176 students and engaged the public in tours and discussions.  Field trips the GROW gallery included content on aquaponics around the best plants for these systems as well as ways the Science Center has worked to create good environments in which the plants can thrive.  Students toured the greenhouse and learned about different aquaponics designs.


Winter 2020—Spring 2021 Aquaponics Lettuce Trial


Seven varieties of leafy and head lettuce varieties were planted in the floating raft in late fall and again where plants had been cleared in early spring. Leafy varieties trialed included Black Seeded Simpson, New Red Fire, Grand Rapids, and Red Sails. Head varieties trialed included Paris Island, Bibb, and Buttercrunch.

Notations documented dates on which plants were either culled for poor performance or bolting or were successfully harvested as a head.

Learning Outcomes

Key changes:
  • May – September 2022: Two Junior Interns were trained in aquaponics and sustainable agriculture, spending significant time in the greenhouse while maintaining the system and adding content to the blog and social media feeds. The YES Teen who participated in GROW in 2021 completed his first year of college. They enjoyed the program so much that he returned in the summer of 2022 and worked as a Science Center employee.

    Students who participated in tours commented on learning content on aquaponic systems, and ways to set up these systems at their schools. They also learned the best plants for these systems (greens, kale, marigolds).

Results and discussion:

Key takeaways from winter:

  • Black Seeded Simpson was the LEAST productive leafy variety with more fungal problems and stunted growth that was quicker to get leggy and bolt.
  • Bibb matured OK but had tip burn.
  • Paris Island was by far the best head variety. We had so many mature at once that we sold 15 heads to Local Harvest mid-January. We could consider a romaine trail in the future, or a succession crop of Paris Island in the future by planting just one raft every two weeks, for example.
  • Several leafy varieties were long-lasting and stayed into the spring, including New Red Fire, Red Sails, and Grand Rapids. Although New Red Fire was long-lasting, it didn’t produce as much as the other varieties. *20 Swiss chard plants were also integrated into the FR during the lettuce trial and performed well into the spring.
  • Some varieties didn’t germinate well enough to trial well and were thrown into the rock bed randomly. Salad Bowl performed well there.

Key takeaways from spring:

  • Heading lettuce varieties were all unsuccessful with super tiny heads and a premature urge to bolt (including Buttercrunch, Paris Island, and Bibb).
  • Red Sails and Grand Rapids were the most bolt-resistant leafy varieties. The over-wintered Grand Rapids ultimately bolted early in the spring, but the newer transplants didn’t bolt until April 28. The over-wintered Red Sails ultimately bolted on April 7, but the newer transplants never bolted and were eventually removed due to heat stress.
  • Additional “heat tolerant” lettuce varieties trialed but rejected in the rock bed include Black Seeded Simpson, Marvel of Four Seasons, Little Gem, and Salad Bowl.
  • Top heat-tolerant varieties include Red Sails and Ice Queen.


  • Reserve half the floating raft for a combo of chard and Red Sails and Grand Rapids leaf lettuce. Reserve the other half for a succession crop of Paris Island romaine. Might also trial Ice Queen for iceberg head lettuce.
  • Kale performed well all winter into June in the lower rock bed. Continue kale production along with misc additional varieties of leaf lettuce if desired.

Project Outcomes

1 New working collaboration
Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.