I strongly suggest AGAINST using standing water. There are to many negative affects that could happen and much safer ways to keep humidity up. For neonates tubs will work great. I am raising an ATB myself and like most who get into arboreal I want to display it. However you would have to continuously change the size of the enclosure as you don't want an enclosure meant for an adult to be used for a neonate. Once they get closer to mid - adult size that is when I will start looking for something more permanent.

Here are some photos that may help:

Tub: http://www.warrenreptiles.com/galler...?g2_itemId=390

I started out using the tub upside down so the inside was more visible but later I changed to right side up as it was easier for feeding. The white thing is just a little dish/utensil drying rack from walmart. Its already coated and meant to withstand moisture. I added some fake vine also. The thing you have to tune is how many holes to put in the tub to allow for proper airflow as well as humidity.