Resources of clean water have decreased significantly in recent years, one of the reasons is water pollution. Utilization of rainwater as clean water resource is among the best option, especially in big cities like Jakarta. Excessive rainwater during wet season can be saved and used as the source of clean water during dry seasons. However, rainwater contains some pollutants, thus suitable treatment method should be utilized to improve its quality as clean water for daily needs. This study compared the effectiveness of zeolite, limestone, activated carbon and preheated 400°C limestone as additive to improve the rainwater quality. Results show that both limestone and preheated 400°C limestone improve all the parameters observed, meanwhile both activated carbon and zeolite had shown to have detrimental effect on water conductivity.