The objective of this study is to examine the feasibility of aquaculture tank heating with geothermal heat pump (GHP) systems. Both closed- and open-loop GHP systems are examined for heating uncovered and greenhouse-covered tanks at three locations across the U.S. A net present value analysis is conducted for a 20-year life-cycle for various GHP base-load fractions with natural gas-fired boiler peaking. The fraction of GHP capacity to the peak load yielding the lowest life-cycle cost is plotted at various GHP installation costs and natural gas rates