Active learning provides students with meaningful and introspective roles in education. However, active learning is difficult to achieve in online class settings, particularly for biology laboratories initially designed to offer direct interactions with live organisms. During the COVID-19 pandemic, a transition to online learning was required in higher education institutions, creating challenges and opportunities to reform and rethink teaching practices. In this article, we report our success in designing and implementing an at-home lab for an undergraduate invertebrate biology course. The objective was for students to learn about cnidarian photosymbiosis in a 3-week experiment using live anemones. Additionally, we tested if learning outcomes are improved when adding a learning-by-teaching experience. We divided the 19 participating students into two groups, where half created videos to teach their experiment to a hypothetical high school audience and half made video reports for their instructors. We observed that the teaching group showed better topic comprehension than the reporting group. Overall, students responded positively to this online learning experience and expressed an increased understanding of cnidarian photosymbiosis. We provide recommendations for implementing this lab with greater success and at larger scales. We argue that adding teaching scenarios in remote learning can benefit students' overall knowledge comprehension.