Throughout the country, there are many bodies of fresh water affected by algal blooms. By focusing on a water source near their school, students can become scientists, too. Situating science content in real and meaningful learning experiences encourages students to be invested in their own learning, construct deeper understandings, and apply those understandings to make the world a better place. This article describes a two-week problem-based unit for third-grade students. The unit was organized as a 5E learning cycle (Bybee 2014) around locally relevant, authentic, inquiry. This structure supported students' understanding of science as a creative and inquisitive process (Crawford 2012). Although it was taught at a third-grade level to meet Ohio's state standards, this unit aligns with the grade 5 "Next Generation Science Standards." Although there are many interdisciplinary connections, English language arts standards are emphasized here. The unit was taught for ~45 minutes daily over two weeks. By taking on the role of research assistants, the elementary students transformed into scientists.