Solar desalination using solar-still is the age old technique to get fresh water from saline and brackish water. The efficiency of the solar-still depends on many factors. The main objective of this book is to show how the output from the solar-still is increased at SRM University. This book presents the complete mathematical modeling of solar-still and solar pond. The book presents how the temperature of the feed water to solar-still and basin water of the solar-still can be increased to increase the efficiency. The temperature of the feed water to solar-still can be increased by circulating the feed water through solar-pond, and the basin water temperature of the still can be increased by using various photo-catalysts. In this work the temperature of the basin water of solar-still was increased by using two different photo-catalysts, 1) Granular activated carbon (GAC) and 2) lead-oxide coatind(PbO2). Experiments were done by using 0.5 kg GAC, and 1kg GAC with 0.5 kg PbO2 coating on the base of the solar-still.The added advantage of this book is, it used MATLAB software for physical modeling of solar-still. Simulink toolbox was used to build a physical model of solar-still.