I would position the UVB on one side about 1/3 of the way down.
If the CHE is on during the day, then you only need a second light source if you need more light. You can use a smaller fixture for this. Definitely add another light source if needed, but you don't need to spring the $ for a second UVB.
As far as night temps, you have a young Sulcata, right? I think 75 to 80 is preferred, so make sure it is actually 75+ IN your tort enclosure. As you know, temps can vary throughout a house. If you want to be safe, having a night heat source will give your tort the option of 80F, or a bit cooler if you have more than one hide.
You have probably seen this thread?
http://www.tortoiseforum.org/Thread-How-To-Raise-Sulcata-Hatchlings-and-Babies#axzz1iGPdl7va
I really like your tort table.
If the CHE is on during the day, then you only need a second light source if you need more light. You can use a smaller fixture for this. Definitely add another light source if needed, but you don't need to spring the $ for a second UVB.
As far as night temps, you have a young Sulcata, right? I think 75 to 80 is preferred, so make sure it is actually 75+ IN your tort enclosure. As you know, temps can vary throughout a house. If you want to be safe, having a night heat source will give your tort the option of 80F, or a bit cooler if you have more than one hide.
You have probably seen this thread?
http://www.tortoiseforum.org/Thread-How-To-Raise-Sulcata-Hatchlings-and-Babies#axzz1iGPdl7va
I really like your tort table.