Starting with a BP

[danielwilu2525]

Hello, I'm new to the forums and my son wants to get a enchi pastel ball python. I heard that they make excellent pets and good companions. We went to go see the snake he wants in a local reptile shop. I concerned when the snake that he brought out had this rain of black stuff on the top of his body. Could these be mites? I'll provide a picture of a close up. I'll be setting him up in a tub (I'll provide a picture of how I want the tub to look like). What size of tub does he need and what size UTH? I already have the thermostat I just need the UTH. Thanks! Oh and do I need to stick the UTH to the actual tub it self or on a shelf?

http://imgur.com/5Fab7Is
http://imgur.com/78HFqzi
http://imgur.com/48LYQKX
http://imgur.com/jymv2Q5

Those are the photos of how the BP looks like, the tub, the close up, and my son holding the snake.

Thanks!