In light of increasing populations and dwindling natural resources, elementary teachers play a crucial role in ensuring children understand and commit to more sustainable lifestyles. Climate change, growing pressures on global fisheries, and the harmful effects of traditional agricultural methods exacerbate this call. Coupled with this emphasis is the need for career preparation that equips the next generation with the 21st-century skills required to support sustainable practices. The aquaponics lesson described in this article addresses "Next Generation Science Standards" (NGSS) as students work collaboratively, integrating such themes as ocean literacy, local and sustainable food production, ecological cycles, and scientific inquiry. The lesson is intended for students in the fifth grade, but could be adapted for both younger and older children. Aquaponics is a symbiotic system that combines raising fish in tanks with cultivating plants in a recirculating ecosystem. Natural bacterial cycles convert fish waste into nutrients for the plants, and they in turn filter the water for the fish. Both large- and small-scale systems can impact the movement toward a more sustainable way of feeding the world's population. The five 90-minute sessions, conducted in an after-school enrichment program, set the stage for students to deepen their practical content knowledge about what fish and plants need to thrive and calls upon their design and engineering skills as they collaboratively create and manage their own aquaponics systems. The authors use the 5E instructional model: Engage, Explore, Explain, Elaborate, and Evaluate.