Sounds like you are using the right lights so a lack of calcium wouldnt be the problem.
There are a couple of turtle guys here so just hang tight as I am sure they will assist you.
It looks like you have a slight case of pyramiding in your turtles shell. What kind of diet do you have your RES on? Do you add any calcium or vitamins to the food? You have a UVB bulb so that is good. All the water turtle that I have ever kept lived outside when it was warm. I never experienced pyramiding in any of them. From the growth of the shell it looks like your turtle might have had the beginings of it when it was younger.
Hes not even a year old, i just got him about 3 months ago and he was just a hachtling. I feed him turtle sticks made by Hikari. I got him this food when i thought he wasnt getting enough nutrient. Its made with everything a aquatic turtle needs. I just dont see why this is happening. I just got him a baby pool so i can put him outside for sunlight. What can i do to stop this before it gets any worse??
you really need to start feeding veggies too turtles need uva as well by the way but im no expert but there is this forum thats where i go about question with my turts