BP tempatures okay?

[Bogertophis]

I think Ruby is using this for control- https://www.chewy.com/zoo-med-enviro...RoCzvcQAvD_BwE

One problem is that it's very hard to control (keep warm enough for a BP) a tank that's 47 gallons, not to mention that glass tanks don't retain warmth very well unless insulated. Ruby- if you cover the sides & back (& also the underside except where any UTH is located) with something that provides insulation*, that will help stabilize the temperatures, but please understand that using this size tank is not ideal to achieve the temperature & humidity needed. It can be done, but you need to make modifications to help.

Such a large air space is greatly influenced by the room temperature where the tank is located- that may be what is complicating the adjustment of your temperatures. Another issue is where the probes are located to measure temperature etc.- and you never rely on what the thermostat is set to- you always need to measure various locations independently to make sure what your equipment is actually achieving.

*As mentioned before, covering the sides (etc.) can provide privacy that snakes appreciate, but at the same time if you use the right materials, it can help insulate the tank to keep warmth in. Many different materials can be used for this, & some are easier to install than others. Things like poster board- the kind with a foam core that comes in black or white in large sheets sold where school & office supplies are sold, also thick corrugated cardboard (which isn't pretty, but you can first install scenery on the glass, & the cardboard behind it), sheet cork or cork self stick tiles, etc. How chilly does this room get, where the snake is located?

Ruby- I wouldn't use lights either- snakes don't like them (they cause stress for nocturnal snakes like BPs) and just the ambient room light is preferable for them. Instead of overhead lights you can use a CHE for warmth without light.

Also, since this is a glass tank, what is on top? A ventilated screen top, I assume? If so, that allows too much air flow, so you easily lose both heat & humidity from inside the tank. By covering most of the screen top (not where the CHE is, of course!) you'll better retain heat & humidity. Keep in mind that when you make any such modifications you'll have to keep a close eye on temperatures & likely make multiple adjustments, since it can take days for warmth to build up after you make changes. (This is the reason it's best to completely set-up & test for a week or more any new reptile home. It's not as easy or safe to do this with "an occupant".)

What are you using for substrate? (I don't recall seeing that mentioned?) As you can see there are so many variables that it's a challenge to help you online, especially when we're not even seeing your set-up.