Terrarium Setup for Boa in SoCal

[SoCalChris]

Okay, I'm having a bit of an issue keeping my new 7 month old Columbian Hypo Boa in a tub (currently Sterilite 32 qt -- Just until I can get a proper enclosure. I would have kept her in a terrarium but everyone is telling me it would be hard to keep the proper temp / humidity in this locale with a terrarium. Truth be told, I'm having ungodly issue doing so with a tub more than I ever did with a terrarium. I have yet to get the temps right or the humidity and am stressing and checking all the time. Does anyone else live in a dry climate and use a terrarium? I'm thinking of at least trying the terrarium.. thoughts?