BLUE TONGUE SKINKS

I just adopted a 10 yr old IJ Blue tongue skink from someone who was moving and could not take him. When I got him he was in a solid PVC encloser, front opening plexiglass doors, with (2) 2" diameter holes in opposite corners for venting and (1) 25 watt UVA/UVB bulb that was permanently attached to the inside of the enclosure. The enclosure was 20 " deep, 4' long and 12" high. It had about 1-2" of cypress mulch bedding and was full of little bugs and the only thing they had in there was a 12x12 slate and a water dish he would soak in.

First thing I did was get a new enclosure I saw on another skink website that was 46" long 18" high and 20 " deep with glass sliding doors. Replaced with new cypress mulch about 3-4" deep, put in a slate wood looking log tunnel big enough for him to lay on or go under plus the original 12x12 slate. (1) 100 watt UVA basking bulb and (1) 23 watt UVB bulb. I also added (1) separate stone food bowl and (1) separate water bowl at the opposite side of the tank from his soaking water.

After (1) hour of the light being on and misting a few times to start the mulch on holding water, the temp is currently 80 degrees and the humidity is 75%

When the previous owner called to check in he flipped out and said I possibly just killed this little guy who is about 18" long.

He said the bugs were to keep him clean. He said he did not change the bedding for 11 yrs and the new enclosure was to big and would not hold heat or humidity.

Did I just do the wrong thing and possibly cause this guy to die or get sick?

Please let me know if I need to change anything or go back to the original enclosure which is to shallow to hold anymore then 1-2 " of bedding.

I believe the temp is a bit low, I'd get the basking area up to at least 90 and make sure he has a hide on both ends. Can you post a picture of the setup?

Here is his enclosure. I now have the hot side average in the 90's with basking stone staying at around 92 with misting 3x a day. The humidity is a battle but it stays between 50 and 90 % through the day. The cold side stays at around 70-80 with humidity on that side staying around 70-80 %.

I did notice his underbelly was red today, first time I noticed it. Does this mean he is getting ready to shed or is there an issue. I posted a picture of his underside best I could.

Skinks often have red underneath. If it's not his normal color possible shed in the near future.
He needs a bigger and more secure hide, best would be one on the warm end and another on the cool end. You can find hides that double as a basking area. I make my own, using a large plastic hide and affixing a piece of bark cut to size on top (the kind that's often marketed as background).