Abstract To reduce the pH vale of the hard water by using the parabolic through collector with the help of temperature generated by sun light in the drought and desert region. The vacuum in the internal portion of the evacuated tube collectors have the reflective coating designed for heat generation encapsulated in the vacuum inside of the tube, which will not damage until the vacuum is lost. This process utilizes the renewable sources to reduce the salinity as well. This paper desalination is done with a parabolic trough collector.