The AquaViewer App displays real time sensor and aux data acquired from YSI 5200A, 5400 and 5500D instruments. Data can be displayed from virtually anywhere using Wi-Fi connectivity over both Lan and Wan networks. Colors are used at App instrument and sensor screens which provide a quick visual regarding node system conditions. Red indicates an alarm condition, yellow indicates a control condition and green (at sensor screen) and black (at instrument screen) indicate an acceptable operating range node system condition. The setup screen is straightforward to configure. Communication occurs either by directly connecting to YSI instrument via Xport device or via communication connection to a PC running AquaManager PC software.