I am currently pricing out costs to get all of my snakes out of the glass tanks and into custom built habitats. I am trying to determine the amount of heat tape needed for each tank. Each tank will house one snake. The dimensions will be 36" x 18" x 12". (Length, Width. Height). The tape I have found comes in multiple widths such as 4", 6" and even 12". I will also have some sort of led interior lighting that will be inside on the top of the habitats. Any advice would be greatly appreciated.