Hello there! I've raised quite a few Leopard frogs from tadpoles. Depending on the size of the one that arrives it's a pretty quick trip from tadpole to tiny frog. A 10gl tank will suffice for eight or so months for these guys, but much after that a 20gl-Long or 29gl will need to be employed. Mine are very active, like to climb and all of that.

If you have a 10gl lying around, use it until you have to go bigger. If not - start bigger.