Just to let all who helped me know, I have found the sweet spot that my turts love to bask in. Also, I have figured out how to post a pic of them. So, thanks to everyone for their input.
Right around 96 degrees. T-Rex goes up for about an hour at a time and Lisa sometimes will go up for a couple of hours and other times continuously climb up and jump off like it's a diving board. It's pretty funny to watch.