Thanks so much, Joanna! I haven't really measured Ash, unfortunately, but I do remember comparing his last feeder mouse to where he's thickest, so based on that he has the girth of about a fuzzie. From my really rough guesstimate the last time I handled him, I would say he's about 1.5 feet.

He was captive hatched, and he's about two weeks old now. (From my understanding, when the store called me to tell me they had hatched new baby BPs, he was born middle of the week before Saturday the 13th, so he's a little over two weeks old.

Alright, I'll take care of the husbandry and be patient with everything else! I'm aiming to get his tank stabilized by the end of today (probably more realistically tomorrow, since I'll still have to see how the temps and humidity go tonight).

Thank you so much, everyone. I feel a little bit better, but I've got some work to do!

--Sam.

Addendum: Oh, and not to belabor the point, but I suppose I just need some affirmation: how does my new setup sound to people? To wit:
Two hides, one for hot end and one for cool end.
Hot end will be regulated by a UTH hooked up to a thermostat, and from above will have a heat lamp that I'll leave on all day (and I'll probably hook THAT up to my dimmer switch).
Cool end will be regulated by a second UTH hooked up to a second thermostat. The water dish will rest on top of this.

It seems I have no trouble getting certain sections of the tank hot so long as I have the heat lamp there, but every time I move the heat lamp, the OTHER end gets too cold. So I figure the new UTH + t-stat should solve the whole problem, so I have complete control over the whole tank. Then I can move the heat lamp to the hot end and just leave it there.