Water is an environmental component that has prominent role for life. Based on the regulation
issued by MoH No.416/ Menkes/Per/IIX/1990 about Requirements and Control of Clean Water
Quality, one of the chemical criterions is no chemical CaCO3 or water hardness. Hard water can
cause renal impairment due to accumulation of CaCO3 and MgCO3 deposits inside human body.
Ketapang leaf, chinese teak leaf and papaya root are example of the plants that contain natural
resin compounds that can be used as a reducer for water hardness.The purpose of this study
was to determine the decrease of hardness level after the water were treated by applying those
various filter media, by conducting true experiment with pre-test post-test with control group design. The study site was in Kalisari Village of Rowokele District of Kebumen Regency. The five
treatment groups under study were: filtration A (ketapang leaves), filtration B (chinese teak leaves), filtration C (papaya roots, filtration D (resin zeolite), and filtration E (without filter media) as
control. There were five replications. The controlled confounding variables were: season, flow
discharge, contact time and faucet outlet. Analysis result by using one way anova test gained a
p-value <0,001; which means that, statistically, the hardness yielded by filtration treatment of
various media types is significant-ly different. The subsequent LSD test shows that the most
effective filtration media is papaya roots, and followed by resin zeolit, chinese teak leaves, ketapang leaves, and the control.