<![CDATA[The water quality of wells in Gadingwatu Village has a high calcium content, which has the potential to cause health problems and reduce the efficiency of household water use. Meanwhile, abundant banana peel waste has not been optimally utilized. This study aims to analyze the effectiveness of carbonized and activated banana peel as a biofilter to reduce calcium levels and improve water quality. The research was conducted in two stages, namely (1) observation, which included the production of activated carbon and measurement of water quality in accordance with Permenkes No.492/Menkes/Per/IV/2010, and (2) experimentation in the form of biofilter application. The data analysis technique used in this study was descriptive quantitative analysis by comparing the average calcium levels and water quality parameters before and after treatment. The results showed that the banana peel activated carbon biofilter was able to reduce CaCO₃ levels from 337ppm to 310ppm, TDS from 356.3ppm to 312.3ppm, and lead metal from 0.24µg/L to 0.13µg/L. The pH value increased from 7.3 to 7.9, making the water slightly alkaline. Characterization of the activated carbon showed a moisture content of 8.44%, ash content of 2.31%, and surface area of 55.44m²/g, which indicates that the data complies with SNI 06-3730-1995. Overall, the banana peel biofilter is quite effective in improving well water quality and has the potential to become an environmentally friendly filtration medium that supports SDGs 6 and 12.]]>
