Fifth-grade students applied their critical thinking skills to plan and design an investigation centered on ecosystems and the interdependence of species. They created two aquaponics systems and explored the question: what would happen if one system lacked a key part of the ecosystem—the fish? As part of the investigation, students formulated a hypothesis, identified variables and constants, and collected data throughout the process. The project is still ongoing, and we are eager to discover whether the aquaponics system with fish will lead to taller and faster plant growth compared to the system without fish.