Detergent waste or greywater is the waste generated from most cleaning products. The existing cleaning products generally contain compounds that threaten the life of aquatic biota, so special treatment is needed in the disposal of their waste. Several studies have stated that activated carbon is a good medium for the adsorption of detergent waste. This research aims to find out maximum ability of activated carbon as a waste adsorption medium detergent. So that the necessary initial analysis of the quality of activated carbon for maximizing the performance of activated carbon as an adsorption medium detergent waste. Iodine absorption analysis can be used as an initial reference in determining the quality of adsorption media. Iodine absorption linearity test using concentrations of 0.025 N, 0.05 N, 0.1 N, 0.15 N, 0.2 N carried out on granular activated carbon which will be used as an adsorption medium. Based on the graphic linearity determination coefficient values obtained at 0, 99. In other words, the absorption of GAC is influenced by iodine concentration, with the correlation between the two variables being opposite. Increasing the concentration of iodine will be accompanied by a decrease in the absorption of iodine. This shows that using GAC as an adsorption medium, it is necessary to take into account the pollutant content of the detergent waste and the contact time of GAC to the pollutant (adsorbate). To be effective as an adsorption medium, the calculation of pollutant levels of detergent waste needs to be analyzed as an initial reference in determining the required contact time. Estimated contact time will affect the design of the adsorbent media for activated carbon-based detergent waste.