But then you'll discover the beauty of tubsI'm not going to say too much because I haven't been keeping balls for long, but from personal experience, aquariums are horrible to work with, especially if you live somewhere that gets cold in the winter. I'm in the process of switching all my balls into tubs and so fars its been incredible. If your planning on keeping him in the aquarium though, your going to wanna cover about 90% of the screen top with plexi glass. This will hold the humidity in. Also you can take the light off the top, it really dries out the air...I think. I also put a thick foam material that I picked up at Lowes and put it on 3 out of 4 sides of the tank to keep the heat from escaping through the glass. And lastly, reptibark isn't the greatest thing in the world. It holds humidity good, but I've found that its horrible to clean and would get in my snakes mouth when he would strike at food. He would freak. I swtiched to newspaper....it doesn't hold humidity well in an aquarium but I have no problems because I'm switching to tubs. I can post a pic of my aquarium set-up if you'd like and also my tub set-up...which was ALOT cheaper and more efficient. I'm sure someone more experienced and knowledgable will chime in to help you as well.
Hope that helped a little! Congrats on your first BP, you WILL get more, trust me...