Critique of Enclosure

[dh1998]

So I've had my baby Leopard Tortoise for about 5 days now, and in the time that Ive had him, I've done a lot to try to make her feel as comfortable as possible. Im hoping you guys can give me an idea of where Im with it and what improvements can be done, and how you would suggest I do it.
ENCLOSURE
To begin I am fully aware it is a glass terrarium (to be more specific its the Exo Terra Natural Desert Terrarium that is 36" x 18" x 12") I chose this one in specific due to its ventilation system and size. I did do my research on the type of enclosure, and started out with a tortoise tub. I unfortunately don't have the skill to build and enclosed terrarium which obviously would be the best choice. So ultimately, after much consideration and advice, I thought the best way to control the environment of the terrarium is using the glass terrariums. I am covering the top with tin foil, but I was going to ask what is the best insulator that I can buy at like home depot for the top? Im using tin foil for now but Im looking for something a little better. The glass is covered on 3 of the 4 sides, I am planning on getting something to cover the front so she feels less exposed.
LIGHTING AND HEATING
For the lighting I have a UVB fluorescent fixture that goes across half of the terrarium, It is probably around 10" from the ground. I have a UVA basking light, which I have adjusted the height to make sure it doesn't get too hot. Right now the temperature under the light is about 107. I am planning however on replacing the bulb with something that also emits UVB. I also have a CHE on the right to make sure that side doesn't get too cool. I was wondering how to keep the temperatures up at night with just one CHE, or should I get another one for the warm side at night also. I did order a thermostat to control the CHE during the day, it is still on its way.
SUBSTRATE
I use a mix of forrest floor and and eco earth coconut fiber. The humidity is at around 57% right now. Which is why Im trying to find a better insulator for the top.
HIDES AND HABITAT
Right now I am lacking in that aspect. I am going to put some plants in there to give her some cover. The water bowl is shallow and i placed it toward to warmer side. I have on hide in the cool side and a humid hide on the warm side.

If there is anything else you want to know feel free to ask!

 

[wellington]

Looks like you have a screen top on it? The uvb will be blocked by the screen. Either remove it or cut a hole in it where the bulb shows thru.
You can do plexiglass for a top but I would stick with what you have. I would get another Che for the other end and put both of them on a thermostat with the probe in the middle. Make the substrate wetter with warm water to bump up the humidity and close of any gaps with the tin foil.

 

[Minority2]

One ceramic heat emitter, depending on the wattage will be able to heat a single 8 x 4 ft enclosure provided that it is in a closed chamber setup. You haven't accomplished this. You've only cover part of the enclosure with aluminum foil. You need to cover the rest. Even a mesh lid with section cut off for lighting fixtures can achieve 80% humidity if it is covered correctly.

You also shouldn't configure your lighting fixtures that way. Half the enclosure is ignored.

---------------------------------------
--Bask----- CHE -UVB fixture ---
hide ------ (optional) ------ food
water ----- (optional) ------- hide
------------------------------- probe
---------------------------------------

Here is a basic setup. UVB fixture on the cool side along with the probe. Hides on both sides. Water dish near basking are and optional spaces for more. Food dish is near the cool side to encourage tortoise to always move towards the UVB fixture for food.