My son's turtle is still eating baby turtle pellets. I'd imagine when a turtle bites the larger sticks, that it will break and you have bits that sink.
Does it look like the stuff on the bottom is equal to the amount you threw in? If not, I'd bet you are seeing the crumbs. Is your turtle passing waste? If you see poo, it's eating.
A three years old, you need to feed more than pellets. Check out the nutrition page on the main site:
http://www.redearslider.com/index_nutrition.htmlI know it has taken my son's young turtle a long time to get used to me, and even now, if I look over the tank when he doesn't know it's me or my son, he flees. We feed in the tank. He'll let us see him eat, and even begs when we come by. But, if I have to take him out, he freaks out, and swims to the bottom as far from me as possible when I put him back.
So, he has gotten used to us, but is still pretty shy.
Where is his tank? Is it somewhere he can see you during the day? I remember that Toby would immediately jump from his basking platform whenever we walked in, but after I took to reading a book in the room, basically being there but ignoring him, he eventually got to where he would bask when I was there and occasionally let me watch if he was basking when I stood at the door and didn't move fast, but still frequently jumped down.
Now that he's in a larger tank in the basement, I never see him bask. But, he will swim over to see me and beg.
From what others have written here, it seems there are definitely personalities involved with turtles. Some are more skittish, but from what I've seen with our skittish turtle, that can lessen over time.