This paper presents experimental and theoretical work, analyzing the performance of single slope solar still with and without a floating lid, conducted in Cairo, Egypt.A Comparison of the experimental output yield with the theoretical one was carried out.The experimentations without the lid were conducted for 7 days and VITD3 BERRY 400IU the daily output yield ranges from (2.8 l/day to 3.
15 l/day) with an average output yield of 52.8 % when compared to the theoretical output yield.To improve the output yield of the still, a black fibrous lid was placed on the water surface and its effect Small animal supplies on the output yield was studied.Because of its porosity the evaporation surface area of the still was improved, water depth is considered small above its surface.
The experimentations with the lid were conducted for 6 days and the daily output yield ranges from (3.1 l/day to 3.3 l/day) with an average output yield of 57.95 % when compared to the theoretical yield.