I am about to buy my first poecilotheria regalis and the temps suggest 75-80 some even say 85.. my house stays about 70-72 during winter but summer my ac unit gets down to 68 upto 70 and I'm aware 68 is to cold but what should I do to bring the tank upto 75-80? I'm thinking about a uth heater applied to the back of the cage set on a timer and seeing as how spiders don't like light I figured this was my only option? I really don't want to buy a portable space heater if I can avoid it