Hello and welcome to FF Ellie ! Bullfrogs need big aquariums; a full grown male can do in a 55G; but a female will need a larger tank. You can use this guide for it's care; other than tank size they have similar requirements: Frog Forum - Leopard Frog Care - Rana pipiens (Schreber, 1782) and R. sphenocephala (1886).