Zebrafish and other aquatic organisms depend on careful monitoring and adjustment of water quality for health and survival. This ideally includes continuous monitoring of several water parameters, including temperature, pH, conductivity, and dissolved oxygen. However, manual readings can be laborious, and commercially available monitors are cost-prohibitive for many installations, especially in small laboratories and classrooms. To address these issues, we have created ZeMo, a high-end open-source water monitoring system that includes a touchscreen, web interface, and email alerts-making continuous water quality monitoring attainable for a wide range of aquarium installations.