Temperature Question

I have a dumb newbie question: Is the hot side temperature measured at the heat source, or is it the ambient temperature? I assumed ambient temp, but after reading some things, I'm wondering if I misunderstood it. Thanks!

You want two readings, one for ambient, and the other is the surface temp where your snake or lizard will lie (belly heat temp). The exact values will depend on the species.

For most snakes you'll want ambient 75-82*F with a basking spot (belly heat from UTH) where the floor temperature can range from 85-92*F.

Okay, so I was misunderstanding a little bit. I knew there had to be a temperature gradient, I just thought the ambient temp on the whole hot side should be where the higher temps are read. The species I'm setting up for is a Western Hognose snake, by the way. I was thinking that my UTH wasn't getting the ambient temp up high enough so I also bought a CHE bulb, but now I will test the UTH by itself again with the thermostat and see if it's right.

A UTH won't increase ambient much. Hognose like to burrow though so if you give it aspen bedding and a UTH set to provide a basking spot on the floor under the substrate of about 86*F, it will be fine.

You would want the substrate to be the hottest area, for BP's, say 92 max. This is the hot area, after that, you try to keep the ambient temperature as ideal as possible, this is usually done by "trapping" some of the "hotspot" heat in the cage by adjusting air flow. Maybe covering a screen w/foil etc...That does not apply to burrowers, then you have to have the bottom of the cage at max if it is underbelly heat, otherwise they can lay on the bottom and get burned.

I have about 3in of aspen bedding in my tank. I've seen such a range of temps for hognoses. A lot of people on one of the FB groups I'm in have said keep the high end at around 92, but I've also had plenty of there people tell me mid/high 80s is okay too. I guess everyone just has to see what works best for their snake?

I don't have my snake yet, but wanted to get everything set up and work out any kinks with heating/light before I bring it home.

That does not apply to burrowers, then you have to have the bottom of the cage at max if it is underbelly heat, otherwise they can lay on the bottom and get burned.

I do have a thermostat to regulate the temp of the UTH, so hopefully no burns will happen. I have a laser temp gun, but feel it might not be entirely accurate for the bottom of the tank, since it's a reflective surface. I guess I should go get a digital thermometer with a probe to make sure the bottom of the tank is correctly getting up to temp, but not getting too hot.

So basically, since hogs are borrowers, I mostly need to worry about the hot spot being in the substrate on one side of the tank, and not worry too much about the ambient temp?

Right. My little hognose is at 85-86*F under the substrate over the heat pad in his tub, with room ambient about 75*F, and he's fine.

Originally Posted by ceruleanblue

I do have a thermostat to regulate the temp of the UTH, so hopefully no burns will happen. I have a laser temp gun, but feel it might not be entirely accurate for the bottom of the tank, since it's a reflective surface. I guess I should go get a digital thermometer with a probe to make sure the bottom of the tank is correctly getting up to temp, but not getting too hot.

So basically, since hogs are borrowers, I mostly need to worry about the hot spot being in the substrate on one side of the tank, and not worry too much about the ambient temp?

Yes, they need to thermoregulate, keep the warm end at the "hotspot", and they will go where they are comfortable. I have seen reptiles with nasty burns from lights etc, so that is something you need to watch for.