1. 1. Quio tie-zhn, 2010 developed online WQM system based on GPRS/GSM. 
   2. Steven silva, Hoang N Ghia. Nguyen, Valentina Tiporlini, Kamal Alameh, 2011 established web based Water quality monitoring with WSN using Zigbee module. The developed system measures different WQP and the data collected send to web server.
   3. Donge He, Li Xin Zhang, 2012 He developed WQM system using WSN.
   4. J. A. Stankovic, 2014 In parallel to WSN, an IoT is developed which combines all the water parameters in order to exchange data and details through data sensing devices (sensors).
   5. Purohit. A and Gokhale U, 2014 developed a WQM system in real time using Intel Microcontroller, GSM ADC, LCD. Due to the difficult architecture of the microcontroller, the developed system is high cost and consumes time.
   6. Beri N N, developed an independent real time device to calculate the water parameter (physical and chemical).
   7. Vijay Kumar N and Ramya, 2015, they developed a water quality monitoring in real time using Iot Environment, as a core controller the system uses raspberry PI.