Be carefull with the UTH...

I would highly recommend at thermostat for the UTH. Some, like my Zoo Med (small) were keeping the top of the substrate (1" Aspen) at a pleasant 90-92, probe under the substrate was reading 115. Ambient temps were low due to current So Cal temps even with a reading of over 100 on the UTH (low 70s). Currently we are switching enclosures (post shed) to a smaller/lower screen top. The old enclosure had this UTH, which I promptly put a t-stat on, as well as a red build hanging from the top and it was inside of the enclosure. This kept ambient temps up, but also could have caused a burn on the snake. Not sure how he got by with 100+ temps on the UTH, an bulb in the tank and low 60s temps. Humidity was also low when cared for by previous owners as he came to us with a stuck shed.

The new enclosure is lower (12" versus 18") but is the same floor dimensions as the other 24" x 14". We purchased a Exo Terra UTH (4 watt) that is being "readied" at the moment and the under substrate temps are reading 91 (under hide, under substrate). Our ambient temps will require some assistance as our home (yes even in So Cal) is reading 72 and the enclosure is reading 78 mid way up on both sides. Some of this will be helped with some aluminum foil. Humidity in the house is pretty steady but during sheds we need to assist (via moist paper towel)

This is probably going to be it for at least a half a year (we guess our BP to be a early 08) and will be going to an RBI 2 x 3 enclosure at 14" tall with the built belly heat or the 11x17 ultrathern heat mat and a the 80 watt radiant heat panel for ambient temps. This would be his domain...

Goal is:
90-94 Hot Side under substrate reading
80-84 Ambient (measured half way up the enclosure)