Determination of the effects natural zeolite clinoptilolite on the aquarium water conditions was assessed in this study. For this purpose 2 different applications were performed. For the first application 7 grams of zeolite (Z7) was put to aquarium directly and for the second application same quantity of zeolite was put inside a net bag (NZ7) and placed in the aquarium. The third group was described as the control group without zeolite (C). Equal amounts of fish feed were added into the aquariums of the three groups and data on water quality parameters (temperature, pH, NH3, TAN) were collected for 12 days. At the end of the trial, level of ammonia which increased in proportion to time was lower in groups with zeolite after day 4, compared to the control group. While no statistical difference was found among mean water temperatures of trial groups (P>0.05), it was found that the difference between pH and ammonia levels was significant (P<0.05).