Louguy510, your turtle is really cute! He looks like a chubby cheeseburger! Doesn't look like he's missed many meals.
Are his eyes irritated? The lids look swollen to me. Does he blink a lot or rub them? If he was living in substandard conditions before you got him, they could have left him with sore eyes. You might try some Turtle Eye Drops. You can get them over the counter at places like PetSmart. They are soothing and will treat minor irritation.
Ditto what was said above about the gravel (big turtle health hazard!) And putting more water in the tank. With that small tank you'll have to work to keep his water clean, and keeping more water in there will help.