Water quality control is essential both before use, to prevent disease, and after use, to prevent the spillage of contaminated water. Although there are sufficient water resources to meet humanity's demand, it is estimated that by 2030 there will be a crisis affecting 40% of the population, therefore it is necessary a proper management of the water resources. While water quality problems exist even in developed countries, poor countries have increasing problems of access to safe potable water, as they do not have the resources to carry out adequate water quality control. For these reasons, it is interesting to apply low-cost and easy-to-build tools to measure or control water quality. In this work it is proposed an Arduino-based cost-effective system for the measurement of several parameters involved in water quality, in which compatible sensors have been used to measure pH, conductivity, temperature and turbidity. The model is focused on portability; therefore, it has been designed with a small size. The implementation of an LCD and SD storage allows measurements to be taken on the spot and to be used as a data logger.