I usinga a heaingpad ( temp ) for my 2 in QT I setit so the pad betwee nthe 2 and it maintaining the required temps I have it set on medium and on a esu control unit. I will be building a small QT rach next summer if I plan on more snakes purchases or rescues. I am close to the limit I set for myself. I used one of those taper drill bits that looks liek a icecream cone ( was on another post ) it works great and theedges are smooth so far. I used it to enlarge a couple holes and add a few new ones to another tub . THey are kinda of high I paid 23 bucks for theoneI got andI seen a 3 piece set for 73 bucks. I can make holes from 1/8 up to 1/2 inch in size.