Welcome to the site!
I just want to say to start that I see a number of issues here, and want to assure you that I in no way intend on making any of the later sound like an attack on you...
I would strongly reccomend you read the
care sheet provided on this website for a complete run down of everything you need and how you should do it.
First of all....
The analog heat and humidity guages have got to go, they are incrediablly inaccurate, and can really only give you an ambient air reading... You can purchase a digital thermomemter with a wire probe for under $10 at your local pet store, or spend a little more and get one around $30 that will give you temp and humidity all in one! These types of thermometer will allow you to get a direct heat reading as well as ambient air temp reading.
Your basking temps initially sound way too low, but I wonder about this since you are only using those analog guages... you need to get the actual temp of the surface of the rock that your BD uses to bask. You also need to make sure you keep those temps between 100-110 degrees in his basking site, in the mid 90's on the hot end of the tank, and mid 80's on the cool side... mid 70's during the night making sure the temps DO NOT fall below 65*... Once you get an accurate surface temp reading, Myself and many others will be able to help you get the lighting right...
The subsrate you are using is very very dangerous to BD's for so many reasons, first and fore most being it's risk for impaction! There are many articles out there on this subject and I will urge you to search them out and read them ASAP. you should really consider throwing all of the sand out, and putting your BD on a solid substrate. (Paper towels, news paper, non adheisive shelf liner, or betetr yet Ceramic or slate tiles are the ideal substrate for BD's)
The reptiglo
UVB bulb that you are using emit very low levels of UVB, and prolonged usage has been known for causing eye problems. You should look into a Reptisun 10.0 for your size enclosure, or better yet look into a MVB (Mercury Vapour Bulb) that produces high UVB levels as well as ample heat for basking.
Hope others will chime in and point out anything I missed, and again none of this was intended as a personal attack, just trying to make sure your handsome little guy is getting the best care possible!
Looking forward to helping you get your set up corrected