10 gallon is a good size for an adult but I must warn you that 10 gallon aquarium/terrariums are natorious for climate fluctuations which can be bad if they get to out of control. The best thing to do with one such as this is to buy a Zoo Med Hygrotherm to assist in managing the climate conditions for you. Combined with a fogger/humidifier the humidity levels are easily maintained and a UTH placed on the side of one end of the tank to heat it. If the UTH isn't enough to raise the temps where they need to be then there are a few more heating additions to help you out.