Vol. 13, Issue 6 (2025)

This study aims to monitor the effect of duration of storage on the physico-chemical properties of harvested rainwater and assess the efficiency of the sand base filtration systems in improving the quality of the stored rainwater. Rainwater was harvested from rooftop and stored for 33 days while monitoring the pH, Total dissolve solids (TDS), Electrical conductivity (EC), and salinity. After 33 days, the stored rainwater was filtered using sand/gravel, backwashed sand/gravel and 100 % sand filtration systems while monitoring the efficiency of each system in reducing TDS. The result indicated that on day 33, pH was 6.23, EC 47.6 us/cm 335 us/cm, TDS 33.3 ppm and salinity 0.17 ppt on day 33. 100 % sand filtration showed a much better performance with TDS reduction of about 60 % in 112 minutes compared to 42 % in 106 minutes for backwashed sand/gravel and 4 % in 358 minutes for sand/gravel system. Results of the physicochemical properties shows that the harvested rainwater can be stored and used for more than 30 days as these values are within WHO levels, and in case of deterioration, these properties can be improved through 100 % Sand Filtration that can be applied in every local community.