Quote Originally Posted by Caesar-A-Squeeze
I read some where that you could place the UTH on the side of the tank is that ok and whats the difference between that and having it under.
Hello and welcome to the forums

Here is a topic I feel I could give some useful advice on. First lets understand the defenition of the term Temperature Gradient. It is defined as the rate of change of temperature with distance in a given direction from a given reference point. Basically, it tells us that if the Temperature at a given point A is 100F and at point B is 50F and the distance between A and B is 5Feet, the Temperature Gradient from B to A = (A-B)/distance. In this particular case it will be 10F per feet, a positive temperature gradient.

Lets look at a scenario where someone decides to put a heat pad smack in the middle of the side of the tank and not in contact with any substrate. This pad will do a good job or heating up the air inside the tank by creating a negative temperature gradient within the system. This means that if you stick your hand just above the side of the tank containing the pad it will be a lot hotter than the opposite end. While this is all hunkey dorey, we want to heat up the substrate so the inhabitant will be happy! With the pad on the side of the tank, the gradient between the bottom of the pad and the side of the tank in contact with substrate will be a negative value meaning that the side of the tank will do a poor job heating up the width of the substrate.

Now if we place the pad on the bottom of the tank, the gradient will be a much bigger value considering that it is heating up the depth of the substrate as opposed to the width. This means that a pad placed underneath will evenly heat up the the block of substrate matching the dimensions of the aforementioned pad, hence providing the desired temperature over a larger surface area. This just means that your snake will be a much happy camper.

Also the generalized notion that hot air rises is misconceived. Cold air is denser than hot air. The cold air forces itself below the hot air hence giving the impression that hot air rises.

So what does all of this boil down to? An experienced keeper will tell you to place the pad on the bottom as opposed to on the side of the tank and that you should take this into consideration before making a decision. Also placing a UTH on the side can cause burns to ur snake! Hope this helped some.

Raj