my probe is on a piece of sterilite tub but the piece of tub is like on the side of the heat tape so i can have free space for my tub. I don't insulate the rack and i think i just said the ambient temperature is around 75-77 in the day. My cool end in the tub is around 77. The reason why its a bit cool is because I have hardwood floor, no carpet what so ever. So it can get cold in the winter and hella hot in the summer.