Please Help!!!

A family living in the desert experiences very hot days and very cold nights. They look at three plans to install system to help stabilize the temperature in their home without using electricity. One is to install a deep little pool of water in front of sunny windows on the south side. The second is to place a pile of stones in the same location. The third plan is to install an indoor pool inside the house. Use the science of heat capacity and thermal equilibrium to explain if the solutions would work and which you think will work better. Assume the mass of the rocks and pools will be the same and assume the same amount of sunlight hits both the stones and outdoor pool. Consider the time of day that each solution would radiate and absorb thermal energy and from where.