Heat placement question

[WaywardSoul]

Hoping for some advice/opinions.

I have a juvie sand boa I recently purchased from a reptile expo. He's doing well, took his first thawed pinkie no problem, etc. Issue I'm having is that we had a cool spell so temps in the house dropped, and I noted correspondingly that temps in his enclosure didn't maintain where I'd like to see them.

He's in a 10 gallon aquarium with a covered lid, a few inches of aspen so he can do as the sand boa do and burrow, and hides on both the warm and cool sides. Heat is currently a UTH on the hot side with temperature controller set to 93, bumped up recently from 90. The probe for the controller is secured to the inside floor of the tank positioned roughly in the middle of pad coverage. So hot side temps I'm happy with as they're staying in range for the sand boa.

Issue I am having is that the ambient has had issues getting over 76, and I noted last night that it actually dropped closer to 72 as the room cooled with our mini cool spell. Hot side pad maintained at it's set temp +/- the two degree range of the controller. I've noted him using the hot side and the areas adjacent to the hot side, but I have yet to notice him using the far/cool side of the enclosure. I'm assuming that with a few inches of aspen it's acting as insulation and keeping it from warming the rest of the enclosure sufficiently?

In an effort to bump temps I've ordered a second pad and temperature controller. Where I'd like advice is placement. Should I place it under the tank on the cool side set to an appropriate temp of say 80? Or affix to the back of the tank to help boost ambient temp in the tank?

My preference is heat pads over lamps/emitters. If I have to go that route I of course can, but I'd rather stick with heat pads if possible. Aside from the lil cool spell we've had and should clear soon the ambients been at 76, but I'd like it able to maintain a bit higher and definitely be sorted before summer is over and cooler nights become standard.

[toddnbecka]

Better to put the probe under the tank, between the heat mat and the glass. As long as there's a warm and cool side the snake can regulate its own temp. Ambient temps aren't critical.

[craigafrechette]

I wouldn't worry as much about ambient temps with a species like a sand boa as I would surface temps. Your snake will spend the vast majority of the time burrowed anyway. That's why it's important to use a temp gun to measure the actual surface temp of the glass, not the substrate. Since your snake burrows down to the glass that's where the temp matters most.

Also, you definitely want to move your probe OUTSIDE the enclosure. It is best sandwiched between the UTH and the glass.
When inside it can be moved, laid on, peed on, etc... which can all lead to inaccurate readings and potentially dangerous heat spikes, perhaps even fatal.

I'm not sure how you've got the probe secured, but I HOPE it's not with tape or any similar adhesive. That can also be extremely dangerous. The snake can actually get stuck, causing horrible scale damage or even death.

[WaywardSoul]

Thank you both for the input