Ali-Sadr water cave is a unique natural phenomenon, which attracts millions of visitors every year (more 15 thousand per day). It was artificially illuminated to attract tourists about 40 years ago. The new conditions have provided the necessary elements such as light; moisture and temperature to growing some organisms (lampenflora). Among them were identified mosses as dominant organism and caused problems to the stalagmites of the cave. Therefore different concentrates of Hydrogen peroxide (H2O2) solution (12.5%, 15%, 20%, 25% and 30%) were examined to control of it. Analyzed date indicated that over 20% concentrations were effective for control of mosses but the 20% was the most appropriate concentration in economic aspect.
