My brother is a reptile specialist. I can get a care sheet done for you. We had a gecko for 4 years and she was in a 20gallon tank which was plenty big for her. What type of gecko is it? Knowing the type could definately help in knowing what size of habitat she will require. Depending on type with also determine what type of substrate and food she can or cannot have. Lighting is also important and heat. A large heat rock is good as it gives a dry heat. And best lighting would be dayglo bulbs for daytime and nightglo for night. Just let me know the type of gecko or even if you can get a pic that would be fine and I will get all the info you need.