Water is a very vital requirement for an organism. Clean water is used for daily requirements whose quality meets health requirements and can be drunk after cooking. The carbonization stage of activated carbon is carried out using a furnace with temperature variation of 400 C and 500 C and then soaked for 24 hours with NaOH 0,5 N. Samples in the form of water were treated by adding cassava peel active carbon with levels of 0,1 gr, 0,5gr and 1,0gr in every 100 ml of water and 0 gr in each control performed 3 repetitions. The result achieved a decrease in Mn and Fe levels of each treatment temperature and adding different activated charcoal, the temperature of 500 C decreased Fe levels between 33.8 % - 93.3 %, Mn 20 % - 92 % while at a temperature of 400 C decreased Fe levels between 26.7 % - 92.8 %, Mn of 16.8 – 91.8%. The result of statistical analysis using ANOVA showed a significant difference in Fe and Mn level before and after the addition of activated carbon of cassava peel at 400 heating and at 500 heating of 0.1 g, 0.5 g, and 1.0 g.