The study aimed to evaluate the efficiency of water treatment using simple indicators like UV absorbance and particle counts. Results showed that just monitoring turbidity was not enough to control water quality, as high turbidity removal did not guarantee low residual aluminum. Monitoring E removal efficiency was effective for assessing water treatment processes like coagulation and nanofiltration for arsenic removal. Additionally, particle counts were useful for determining the need to change coagulants in real water treatment scenarios.