My first gecko I was keeping in an 20 gal long with an appropriate sized UTH (zoomed). I found that as winter approached he stopped eating and would not come out of his warm hide. I moved him to my rack with a bit higher and much more consistent temps and he began eating within a few days. While aquariums are great for viewing the do not hold heat well at all. If you were ever to consider getting another gecko you should think about getting a rack. There is a bunch of debate about them but I personally believe that my geckos are much more comfortable in them.
