One of the most economical ways to reduce ions is to use cheap ceramic adsorbents instead of expensive resins. In this thesis, the performance of natural zeolite and activated alumina to reduce water hardness is investigated. NaNO3 and H2SO4 modifiers have been used to improve the performance of the adsorbents. To show the efficiency of these adsorbents, laboratory variables affecting the adsorption process such as column diameter and water flow rate were investigated. According to the experiments, the optimal column diameter was 1.5 cm and the optimal flow rate was 10 ml/min. The results showed that the maximum reduction of total hardness, calcium hardness and magnesium hardness were 99.97%, 99.96% and 99.93%, respectively, which were obtained by natural zeolite adsorbent under optimal conditions. The observed time for breakthrough by natural zeolite adsorbent is in optimal condition and for total hardness, calcium hardness and magnesium hardness are 120 minutes, 120 minutes and 110 minutes, respectively, and for active alumina adsorbent are 50 minutes, 100 minutes and 180 minutes, respectively. In addition, the substrate saturation time by natural zeolite adsorbent for hardness, calcium hardness and magnesium hardness was 570 minutes, 540 minutes and 570 minutes, respectively, and for active alumina adsorbent, 450 minutes, 510 minutes and 570 minutes, respectively. According to the results, the time duration observed for Breakthrough is 240 minutes, 180 minutes and 450 minutes for total hardness, calcium hardness and magnesium hardness, respectively, and for the optimal state of modified active alumina adsorbent, 180 minutes, 140 Minutes and 80 minutes observed, respectively. In addition, the substrate saturation time by the modified zeolite adsorbent for total hardness, calcium hardness and magnesium hardness is 600 minutes, and for the modified active alumina adsorbent, 570 minutes, 510 minutes and 510 minutes, respectively. According to the results obtained in