There are many dams have been established in Turkey for different aims such as electric production and irrigation. It is also benefitted from several of these dams by growing trout fish. However, the temperature of most of these dam lake water is high, particularly during the summer hot season period (from May to September) for growing trout fish. In order to cool the water of fish growing floating pool or tank by pumping cool water from depth of 25 m, a solar powered trout fish growing system that previously designed for Ataturk Dam Lake and an on-grid power system have been selected. The solar powered water cooling system mainly contains monocrystalline silicon solar panel, MPPT (maximum power point tracker), battery pack, inverter, and a submersible pump. In contrast to many components of solar powered water cooling system, to operate the submersible pump, only the electrical network as well as a control panel are required for on-grid system. The needed PV panel area, water pump power and energy during system lifetime are also determined for one fish growing unit (floating pool or water tank) by considering some technical various data. The reason for choosing as a sample of Ataturk Dam Lake for this study is that Ataturk Dam Lake is established on the Euphrates River and ranked in the first ten amongst other dam lakes in the world. The economic analysis of both these systems have been made and these systems have also been compared with uncooled (naturally cooling) system in this work. The results of the study showed us that in order to economically functioning of a small scale or a private fishery enterprise, the required minimum number of fish growing tanks are 19, 17 and 15 for solar powered cooling system, on-grid cooling system and uncooled system, respectively.