Arvin Anthony S. Araneta, International Journal of Computer Science and Mobile Computing, Vol.11 Issue.3, March- 2022, pg. 152-165 © 2022, IJCSMC All Rights Reserved 152 Available Online at www.ijcsmc.com/journal International Journal of Computer Science and Mobile Computing A Monthly Journal of Computer Science and Information Technology ISSN 2320–088X IMPACT FACTOR: 7.056 IJCSMC, Vol. 11, Issue. 3, March 2022, pg.152 – 165 Design of an Arduino-Based Water Quality Monitoring System Arvin Anthony S. Araneta, DMT College of Computer Studies, Eastern Samar State University – Salcedo Campus Salcedo, Eastern Samar, 6807 Philippines DOI: https://doi.org/10.47760/ijcsmc.2022.v11i03.017 ABSTRACT In agricultural cultivation, water is a critical climatic element. It has an impact on the growth and development of plants. Their abundance or shortage can lead to a good harvest, a lower yield, or even failure. Water quality testing is an essential part of environmental monitoring. When water quality is inadequate, it has an impact on agricultural life as well as the biological system as a whole. The researcher decided to design, build, and test a device that would enable real-time water monitoring based on this concept. After five months of research and development at Eastern Samar State University Salcedo Campus, the device was finished. The Arduino-based Water Monitoring System is entirely functional and can detect sensor readings from four parameters, including temperature, pH, turbidity, and electrical conductivity. According to the experiment results and the system usability test, it can now be deployed. The gadget also has an ESP32 included in it, which can transfer data through WIFI and Bluetooth. The device was practical and usable because it complied with the specifications. When paired with the Water Quality Mobile Application, the device is compatible with a 5-volt power bank and works well. The researcher suggests that digital sensors be considered because the gadget employs analog sensors, and reading is completely dependent on the type of sensor used. Additional testing, such as monitoring the ammonia level and dissolved oxygen, can be done while considering the device power requirements and overall design. Keywords: Arduino Device, Water Quality Monitoring, developmental design, smart agriculture, Internet-of-Things I. INTRODUCTION Background of the Study Republic Act (R.A.) No. 9275 (2004), titled "An Act Providing for a Comprehensive Water Quality Management and Other Purposes," otherwise called the Philippine Clean Water Act of 2004 (CWA), was marked by previous President Gloria Macapagal-Arroyo on March 22, 2004. With its Implementing Rules and Regulation (IRR) contained in the Department of Environment and Natural Resources (DENR) Administrative Order (A.O.) No. 2005-10. The law applies to water quality administration in all water bodies. It