UTH heat question

SO im finally setting up one of my tanks and im running into a few questions about UTH heat.

I use the zoo med UTH and its pretty thick. With the probe underneath it, there's a significant amount of the pad that isnt touching glass because the herpstat probe is so thick and the thick pad cant just stick around it. I have the herpstat set to 100 degrees, which I think is too high, but the thermometer probe on the other side of the glass is reading 89, and on top of the thin layer of substrate is 82 (thermometer gun).

One thing to note, I dont have my RHP installed yet, so the ambient is 75ish. My questions are:

1. will having the RHP installed, keeping temps at 80-85, will it raise the temp of the hot spot as well to something more suitable?

2. Is this gap caused by the probe making my hot side not heat enough?

3. Im aiming for a hot spot of 92.. should my substrate be reading 92 or just the glass? Does it even matter as long as the t-meter probe is reading 92?

4. What temp do you have your t-stat set to, to get your glass and substrate to read properly?


Thanks!

I don't have a setup like this, but I'll try to answer to the best of my knowledge...

1. If you have an appropriate sized RHP for your enclosure, you should be able to keep ambients in that range with no problems.
2/3. You'll want to control the temp of the surface of your enclosure. It's likely your thermostat will be set higher than 91 in order to get the surface temp to 91 or 92. The top of the substrate may be a tad cooler. If you have a substrate that your snake can burrow in, you'll not want the surface of the tank higher than 92 or you risk the snake getting burnt.
4. This just takes time to figure out. It depends on the type of substrate you use, how thick it is, how much moisture is in it, etc...

Thanks. Im not really worried about the ambient temps, im just thinking ahead wondering if the ambient temps being 6 degrees higher will also increase the top of the substrate on the hot side's by 6 degrees. That would work out to about what the glass temp is. I dont have my plexiglass yet so I cant bolt it and find out for another week or 2.

Edit: My substrate is eco earth.. im a little surprised at how moist the stuff is.

How tall is your enclosure? What is the overall size? What size RHP do you have? Some folks only use an RHP and don't fool with belly heat at all.

Enclosure is 18 inches tall, using a 40 watt in a room thats already about 75degrees. RHP should easily be able to get the ambient to 80