This paper presents an extension to an IoT platform for remote near real-time aquatic environmental monitoring that incorporates electrical conductivity (i.e., salinity), dissolved oxygen and potential of hydrogen (pH) sensors. The predecessor to this system could be remotely deployed for extended periods of time, but was limited to measuring temperature, lux (light) and turbidity only. This paper outlines how the platform was expanded upon to include the additional environmental parameters (i.e., salinity, dissolved oxygen and pH) by selecting the appropriate compatible sensor technologies, redesigning the electronic componentry/physical buoy, and undertaking thorough system integration testing. We present the hardware and software challenges faced to adapt the platform to the new sensor parameters, illustrate the latest buoy design, describe the calibration process and demonstrate in-house and commercial field-testing. The system can be deployed for 12 months between maintenance cycles and has been used in environmental research and commercial prawn farm water quality monitoring.