The experimental analysis aims to investigate ways to protect a water pond, in order to reduce bottom pond temperature. For this purpose, three identical shallow ponds are together recorded in moderate climate. The bottomless ponds are placed on a concrete roof, exposed to the ambient conditions. Water depth is kept constant in 0.10m, while each pond has an area of 1m2. A number of alternative materials for water protection are tested: white textile, the textile used in ironing board, aluminum layer, aluminum foil and insulation. Some of the materials are keeping afloat on water level, while other are kept below or above water level. The analysis focus on the devices that give the lowest temperatures, thus the most effective ones. The bottom pond temperatures are analyzed, in regard to the climate. Furthermore, the bottom pond temperatures are also compared to the temperatures below an insulation layer placed on a concrete slab. According to the experiments, protecting water with reflective materials can reduce bottom pond temperature, thus increasing cooling efficiency.